On one hand, it's amazing to see that the boundaries of technology are moving so fast that someone could come along a year after Oculus makes big news with something that might blow them out of the water (according to marketing hype).
On the other hand, $500M for an unlaunched startup with no users is crazy. That money could be stretched so far in so many ways and it's being dumped into a company without a dime in revenue. There is clearly no attempt to be 'lean'. It's hard to believe that they really 'need' $500M to develop this new tech, they're not flying to space and they're not pushing a medical device through FDA trials.
I guess the best thing to do is sit back and watch.