After months of waiting, and the past several weeks packed full of rumors about its forthcoming arrival, it was looking like updates to Windows Phone 7.8 were just about to arrive. Last week, we saw the most convincing evidence yet, making the case for the updates to start going out today, January 30. Sure enough, Nokia has just posted a message to its blog making the release official, starting distribution today and continuing into next month.

Nokia says that owners of the Lumia 510, 610, 710, 800, and 900 can all look forward to seeing Windows Phone 7.8 updates arrive over the course of the next several weeks, pending carrier approval.

Of course, this still leaves open the question of the WP7.8 fate of non-Nokia handsets, and considering the recent news from HTC about the HD7, there’s some cause for concern. A new rumor claims that Microsoft might make the bold move of sidestepping the manufacturers and delivering WP7.8 through its own will. Problem is, that rumor said to expect the software to start going out as of two hours ago, and we just haven’t seen signs of that happening. Either it’s a dud, or the timing’s off.

Update: Well, there might be something to that rumor, after all. We just got a report of a Windows Phone 7.8 update arriving for an owner of the HTC Radar.