So Verizon (NYSE: VZ) finally got its hands on the Apple (Nasdaq: AAPL) iPhone. The biggest champion of Android phones now has much less incentive to sell Androids and a whole lot of motivation to put marketing muscle behind the iPhone instead.

Game over, Google (Nasdaq: GOOG)?

That would be the obvious snap judgment of the situation as disgruntled AT&T (NYSE: T) customers make the pilgrimage over to Verizon only to pick up a more reliable version of the phone they already know and love. Apple's share of the smartphone market should increase dramatically, even if you count on millions of customers simply buying one iPhone to replace another. After all, many a potential user must have stayed on the sidelines with a temporary Droid or something, just counting the days until Big Red could deliver on their dreams.

But then you're overlooking another moving part in the share puzzle: What will AT&T do?

You can't expect AT&T to sit idly by. The company has put the vast majority of its smartphone efforts into the iPhone so far, but now suddenly has reason to sell Androids, Microsoft Windows Phone 7, and Research In Motion (Nasdaq: RIMM) BlackBerry phones. Verizon famously poured about $100 million into promoting the original Droid in 2009, and the Droid line has performed admirably ever since. Would you really expect AT&T to do anything less for a rivaling platform now that the iPhone is a polygamist?

Recent news says it won't be. The company threw its support behind Android at the industry's CES event last week, highlighting more than a dozen new Android phones. Among these was the powerful Motorola (NYSE: MMI) Atrix smartphone powered by NVIDIA's (Nasdaq: NVDA) Tegra processor. Expect the Atrix and its Android brethren to get a promotional bump in the coming weeks, especially since AT&T will be promoting these new phones along with a faux-4G network upgrade.

The pull of Verizon's network is very real, but it will be counteracted by AT&T's counterstrike. The net effect is a multi-horse race, depending on exactly where AT&T places its bets. Apple will grow, Android will grow, and maybe even Microsoft gets a toehold in the market at long last. The only question is which platform grows faster than the others in an expanding total market.

The Verizon iPhone won't kill anybody or anything else. This is just another shot of intravenous caffeine for smartphones in general.

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Fool contributor Anders Bylund owns shares of Google but holds no other position in any of the companies discussed here. Google and Microsoft are Motley Fool Inside Value picks. Google is a Motley Fool Rule Breakers recommendation. Apple is a Motley Fool Stock Advisor selection. Motley Fool Options has recommended a diagonal call position on Microsoft. The Fool owns shares of Apple, Google, and Microsoft. NVIDIA is a Motley Fool Stock Advisor choice. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. You can check out Anders' holdings and a concise bio if you like, and The Motley Fool is investors writing for investors.