Back to the Future 2 *clearly* showed that we were due to have flying cars in 2015.
Of course, they also showed the Cubs winning the World Series, and I can't see that happening in 5 years, either.
So if they hold true to what Bill Gates said (http://www.esato.com/archive/t.php/t-54833,1.html) back when they were just a software company, this device should cost us nothing.
The other thing is Microsoft's last announcement of something like this (the tablet PC, wasn't it?), turned out to be something you couldn't buy. It was a reference platform and a set of specifications that others could build to.
So I'm not holding my breath that we'll be able to buy one of these.
I am a computer. I am dumber than any human and smarter than any administrator.