Windows Phone 7, which has only been available in the U.S. for around a month, hasn't received any kind of OS update yet, but there have already been a couple of big updates rumored to land early next year.  Today another big update has appeared in the rumor mill, courtesy of Mary Jo Foley at ZD Net.  Foley's sources are reporting that this update is codenamed "Mango" and will be even larger than the upgrades coming early next year.  Mango is said to include Silverlight runtime, HTML5 support, Far Eastern language support, and other unnamed features.  In fact, there's so much packed into Mango that Foley's sources are saying that it'll basically be like Windows Phone 7.5, and that it may actually end up being called that.  If that's not enough for you, Foley is also reporting that Windows Phone 8, codenamed "Apollo," is planned for late 2012.

Considering that Microsoft released Windows Mobile 6, 6.1, and 6.5, it shouldn't come as a surprise that they've got Windows Phone 7.5 coming up at some point in the future.  It's tough to predict just what'll be included besides what we already know, although I wouldn't bet on a UI overhaul like we saw in the move from 6.1 to 6.5.  Mary Jo Foley suggests more enterprise support, which seems like it'd be a good idea for a couple of reasons.  Windows Mobile was pretty popular among business customers, and I'm sure that they wouldn't mind sticking with Microsoft for their mobile needs.  Plus, we've seen time and time again that RIM has been losing market share to competing OSes.  Sounds to me like an opportunity for Microsoft to grab some share for itself in a hurry.

Via Engadget, ZD Net (Image via PCAdvisor)