I was a bit skeptical to think the responsiveness of the UI would be as fast as we've seen. But wow, after seeing this AND it being just a devkit. . . I'm impressed.
However they could have shown something more useful than IE
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"[url=https://twitter.com/albertpenello/status/395726844533559296]This is an old XDK build. Not up to date. Game doesn't get squeezed like that and it's super slow. Current builds WAY faster[/url]."