Amongst all the hype for Windows Phone 7, Skype doesn't seem as enthusiastic as everyone else, and they're letting it be known. According to reports, the extremely popular VoIP software company has decided to abandon the upcoming Windows phone software and focus their efforts onto Symbian, iPhone, and Android. They also recently canned their support for the Windows Mobile platform. There is no explanation for Skype's abandonment of Windows Phone 7, but there are quite a few reasonings that could be to blame. According to Kelly Hodgkins of BGR, “...the decision could stem from WP7’s lack of native code and its tight integration with XNA and Silverlight for development. It also doesn’t help that Windows Phone 7 is a new and untested platform.” If I was a developer, I would be very hesitant to spend time and resources for a new platform if I wasn't sure how it was going to take off, too.
With that being said, if you were looking forward to Windows Phone 7, and are a heavy Skype user, you may want to rethink taking the plunge right away; there is always hope of Skype support for WP7 later on.