The unit itself barely gets warm, even after using it for hours. Would you happen to know if using a live wallpaper would use a lot more power then a still one. I'm guessing yes, but would it be noticable? Also, let us know if your unit powers back on in about 30 seconds after powering off.
My understanding is that it is a variable speed CPU which speeds up as the workload goes up. Live wallpaper will mean that the CPU will be running at a higher cycle rate and that will be more heat. I have no idea how much. Personally, I never put stuff like that on my computers. In addition to CPU overhead, at least on Windows boxes, they are more likely to be glitzy and cause lockups and other abnormal stuff.
I'll post a review when I get my G4 and will include the remote shutdown behavior. I wish it would arrive soon. It was in the People's Republic yesterday and Hong Kong this morning. I hope it is on an airplane now but I fear it is on the proverbial slow boat from China.