Every member of the press that was present at the event got the opportunity to try it on and use it for themselves. Every one that tried it said it totally blew their minds. It worked, and they weren't expecting it to.
Why don't you people read a review from one of the people that actually tried the darn thing on? Plenty of them on the net.
Processing Terabytes in real time? Yeah, they invented new processors to be able to handle that. Combined effort from Microsoft, JPL, and NASA to develop the tech.
Spew all the anti-Microsoft BS you want, and claim Microsoft is making a mistake or whatever, but this is something that is already running Windows 10 early builds and it runs Windows 10 universal apps.
The reporters that got to try it were able to not only step onto and walk around a martian landscape in real time, they were also able to play Minecraft. It's not all just renders, it is reported as actually working.
The real thing we have to wait on is final product battery life and things like that. It won't be released until after Windows 10, because it runs on Windows 10.