On fps, here's an excerpt from e-fotografija's review of Canon 40D

"As said before, the rapid fire mode won't be used that often by the camera's target public. Sure, it's fun to play with it and show off in front of your mates, but how often do you really need it? You might go all Tim Page (this translator's favourite war photographer ever) and leave the camera on 6.5 fps all the time, just in case Elvis pops up from somewhere. On the other hand, this means that you'll probably take two shots instead of one, which isn't all that good for the shutter. But then again, the shutter has a life expectancy of about 100,000 shots, so it's not too much of a worry. And in any case, you still have the option of using the sane speed, 3 fps."