Call it a Hail Marissa pass.

Kudos to the Yahoo board for shaking up the conventional wisdom, going long, going young, and going Google. Against a history of failure, it has chosen success — the gold-plated success of Google — and thrown both Yahoo watchers and staffers for a loop. The onrushing changes at Yahoo have seemed almost Marxist — as in Groucho — as troops have been led this way (let’s dominate the display ad market through the wizardry of our integrated bought-and-built ad technology) and then back again, as ad staff has been laid off, cut back, and told that ad-tech outsourcing was on the horizon.

Yahoo as product company. Yahoo as sales company. Yahoo as digital Hollywood company. Watching the parade of costumes has been like peeking at those silly old-timey Western dress-up booths at county fairs.

Yahoo — despite its $5 billion in annual revenues and a billion in net profit — seems like the Rodney Dangerfield of media companies. It just can’t get no respect. So why not try to buy a little respect?

37-year-old Marissa Mayer has known little but success, and the emerging respect and self-confidence that accompanies it, since she joined Google as a 24-year-old. She brings something Yahoo badly needs: an aura of success and of discipline. That’s a start, as she takes on the challenge of what is a legacy web company. Number one by traffic, Yahoo seems as much a legacy company as a newspaper or local TV station — legacy as in the encumbrance of long-time, if fading, success. Its legacy is the desktop. It survived Excite, Lycos, Infoseek, Netcenter, and many more. In the seeds of its own success as a portal, it’s found out how hard it is to transition from the portal era. Now, as Google, Facebook, Amazon, and Apple come to dominate our lives — and our pocketbooks — with the four dominant S’s (search, social, shopping, software) of our time, the portal is rapidly diminishing in value.

That question — what is Yahoo? — is, in a sense, the only one Marissa Mayer needs to answer. Her five predecessors in five years failed at that seemingly simple task. Answer that question, and the strategic, product and organizational decisions flow from it. Fail to answer it, and imagine your portrait alongside Scott Thompson, Carol Bartz, Jerry Yang, and Terry Semel.

As we look at the news of the past week — an amazingly busy July, testimony to the acceleration of media change in this year — we see that identity question popping up all around. Within the question is the newsonomics of identity: what does a media brand mean these days?

NBC’s first step yesterday, following its long-brewing divorce from Microsoft, was to rechristen its MSNBC.com news portal as NBCNews.com. While some have suggested that divorcing it from the left-leaning MSNBC channel is the primary reason, certainly the re-ascendance of — and concentration on — the NBC name makes even more sense. NBC has brand equity, nationally and locally — and it will soon have greater global resonance. MSNBC has never rolled off the tongue. Now NBC, with strong intact leadership (Steve Capus, Vivian Schiller) can move forward, backed by the might of owner Comcast, as it competes with other global news players, including the Times, the Journal, the BBC, ABC, Bloomberg, Reuters, AP, and the Guardian.

Brand identity also runs through the other big media story of the week. As Tribune Company finally emerges from bankruptcy, drip by drip, the question re-emerges: What is the Tribune Company? Is it eight daily newspapers, the core of what Tribune once meant? Is it those papers and its 23 broadcast stations — which now out-value the newspapers at least three to one — and Career Builder? Or: Does this company still have a reason to stick together? We can point to technology and infrastructure ties as a reason, but these may well be overwhelmed as assessment of individual property values is made by the new ownership, financial players who want out.

Certainly, the Tribune means something in Chicago, the Times in L.A. (where no one needs to tell would-be buyer Eli Broad about the value of that brand), and the Courant in Hartford. What’s the print/digital brand promise, though, to readers and to advertisers in 2012? That’s a more difficult question, and one symptomatic of newspapers, and increasingly local broadcasters, current market woes.

Identify. Promise. Brand. These are issues have been bedeviled Yahoo for years now. In a world of changing media and consumer devices, the ability to make a promise and fulfill it better than anyone else is the key to success. Which is why that quartet of Google, Facebook, Apple, and Amazon are winning, and most of the rest of legacy web media, legacy print media and legacy broadcast media are losing.

As Mayer moves 5.5 miles mostly east to her new Sunnyvale office today, she will briefly enjoy her wunderkind status. Then, we’ll see how well her detail-oriented, user-centric mindset can effect change. Sure, Yahoo has lots of good products — she has already cited finance and sports — but what great, clearly ahead-of-the-pack ones does it have? Where can it pick its spots? In business, it is outgunned by Dow Jones, Reuters, and Bloomberg. In sports, ESPN, MLB, Comcast, and Fox are pouring in huge resources. New partnering — built on the ABC and CNBC deals — may help, but isn’t everyone doing those kinds of deals these days?

Is there something distinctive that Mayer can bring to the Yahoo user experience?

I suspect that new focus will be distinctly mobile. Tablets and smartphones are the new playgrounds, with lots of eager and less-habituated readers and viewers. Individual news, business, and sports brands have been ascendant on the tablet, as the old aggregators (Google Currents, AOL Editions, Yahoo’s Livestand, on which it recently pulled the plug) have failed to transition their desktop advantages over to the new medium. Is there a Google-simple trick Mayer can find up her sleeve to differentiate the newest Yahoo and please the hell out of consumers?

Beyond that customer-centric enigma is the big question of what kind of advertising company Yahoo wants to be now. If it pursues ad outsourcing, that only puts more pressure on it to quickly create more products that are at least insanely good. If it stays in the ad game (even as its display competitor Microsoft is acknowledging its own ad futility against Google market dominance with a big writedown), how will it compete? Does Mayer, a strategic builder of technology solutions, reverse recent course and re-commit Yahoo back to advertising focus? Will it try to hold on to its partnership with half the U.S. daily press, through the Newspaper Consortium, as those members begin to contemplate the mature deal that may well pass into history by the end of 2013, if not sooner?

What has the experience of leading Google’s latest push into local advertising taught Mayer? Google Maps, Google+, Google Ad Words Express, Google Zagat, Google Places are all meshing into Google Places for Business, meaning a better place for local merchants to invest their marketing dollars — with Google. Is the Men in Black memory eraser part of Mayer’s Google contract? Or will Yahoo, and its news partners, benefit from her recent experience?

We’d have to believe that the odds against Mayer are long. She inherits a mess, and she’s an inexperienced CEO. She knows product, but she’s not a deal-maker. She’s got the experience of one great company, but no other. The game is newly afoot though, and therein lies the serial pleasures of Yahooing.

Photo of Mayer by J.D. Lasica used under a Creative Commons license.