First silverlight, now this.
Why should I invest in the Microsoft stack? I'm done. Microsoft is no longer a platform I will work on and I will recommend open source products and frameworks from now on.
Can you imagine spending 5 years learning XNA and becomming a guru, only to have them yank the rug from under you?
Oh you have experience in XNA? You might as well have experience in Visual Foxpro.
F-U Microsoft - from thousands of XNA devs worldwide (including myself)