magicalclick said:

I have never consider it alive to begin with. I never understand why they even make such eleborate video to begin with.

Speculation from a few comments on Engadget. 

 

MS was hoping to slow iPad sales by releasing more videos and leaking a 'tentative release date'. 

 

I think they were going to release something, but realised that with their partners deserting Windows left, right and centre then they could no longer afford to introduce another OS paradigm.