Today's demo that showcased Microsoft's application of cloud computing to gaming definitely impressed many, and the newly appointed Xbox division head honcho Phil Spencer mentioned on Twitter that he's aware that the capabilities of the cloud need to be proven, promising that more will come:

Yea, I'm aware that we need to prove to people, that's fine. BUILD demo was a step, we'll have more.

Spencer also mentioned (apparently risking to get in trouble as it seems this may be a rather relevant revelation) that today's demo wasn't just throwaway work, meaning that it's probably part of a bigger project, possibly a game.

I'll get in trouble (I guess fewer people to bust me now...) but the demo today wasn't throw away work.

When asked if it was a game in progress, the response was a teasing "give us some time."

He also explained how the demo actually worked on a technical level:

Demo does cloud physics calc for destruction based on random shots to building. Local is render of pieces based on cloud loc data.

Spencer also clarified that his promotion could change Microsoft's plans for E3 slightly, but not by much, as it was already supposed to be all about games:

Maybe a little but no big changes. E3 was always going to be games focused.

Finally, he elaborated on future plans, also teasing a couple unannounced games and visits to third party studios next months:

Still believe exclusive content is a key to console success. No change there.

We expand when we have a great idea to build. We've been doing this with a few things lately.

I agree, our 3rd party relationships are critical as well, I'll be doing visits in the next month, new thing for me.

Lift London is another. A couple unannounced.

I, for one, found today's demo definitely interesting, and I'm eager to see where the technology will go. Maybe we'll get to see more about it at E3. Hopefully it'll keep impressing as it did today.