Talk of Microsoft finally deploying Windows Phone 7.8 has been building to a crescendo -- and we're glad to confirm it's more than just noise. The more customizable home and lock screens, Marketplace improvements and numerous under-the-hood upgrades are rolling out to all of Nokia's Windows Phone 7.5 devices, starting today and continuing through February. The company hasn't confirmed who goes first, although AT&T's Lumia 900 is believed to be part of the earliest wave. Other upgrades will depend on carrier timing, if you're using a locked phone, but the plan to push 7.8 is still good news for those who've wanted to keep their early Lumias as current as possible.