Not to likely they'll have them at a high enough res for my taste any time soon. It's also not likely that there will be one subtle yet cool enough for my tastes either... That said, I can see the appeal, something that looked like the "Enigma" table from the old Epic pinball might be cool (if it was subtle), but then it might as well be a rendered thing and not a looping video... Something like a galaxy background with cosmic things going on might be night too (think Homeworld), mostly dark and unobnoxious but with the occasional "wow that's pretty" event... Again, probably better as a render, and it would need to be really hig res...
The CPU/GPU usage doesn't bother me, as long as it was smart enough to not effect performance if it was completely covered by a window. What else am I going to use up my CPU on if I'm not gaming or encoding?
GUI desktops gotta start advancing sometime of we'll never end up with Minority Report esque setups...
Edit: Oh, and they would have to be free of course, I'm not paying for that crap. 