Looks like the 560 Ti is about 25w less power use than a GTX 470. According to the review Tomshardware posted on their site. Performance wise they look virtually identical. However, although Toms didn't do a temp test/chart, I'm going to presume the new 560 Ti runs a bit cooler.
Nice. I figured so. It has a lot less heat producing components packed into it when you look at the specs. Obviously nVidia has refined Fermi quite a lot. Less ROPs, processing clusters, etc. Yet the same performance as the 470.
For someone who never made the upgrade, the 560 Ti should be a great choice to get good performance without all the heat issues.
It's interesting though, that the 560 Ti only uses on average (according to Tom's) 25w less power. This is probably due to the fact that they bumped up the core clock speeds quite a lot compared to the 470. Less hardware for processing, but what's there runs a heck of a lot faster. So it still uses a bit of power.