Indeed! This is kind of MASSIVE, we now basically have what is probably the smallest, cheapest, fully unlocked full-fledged media player, capable of handling what appears to be just about anything you can throw at it, short of 3D video (and possibly very high-bitrate streams), EVER available (or, in this case, almost available)!
To think this kind of thing would be undreamed of just five or six years ago (heck, it still baffles me today!) and watching it happen now, is just AMAZING!
Now, I hope the XBMC team (or whoever is porting it, but I'm assuming the XBMC team is involved) will be able to get it a bit smoother (and easier on the CPU), or at least someone will get a very lightweight skin on it, so you don't notice the small hickups.
Congrats to both the R-Pi team for creating this beautiful thing, and the people handling the port of XBMC to it.
Wow... Just... Wow...