Choose your camera according to your needs. What are you going to be taking pictures of? We all do different things. Which is why I disagree with FX101.

3200 ISO is VERY useful - even essential - if you're going to do photos indoors of things that move quickly, and you can't use flash - stage productions and sports are two examples. Even with a f2.8 constant zoom wide open you're hard pushed to get above 1/180s and when you're working at the equivalent of 200-300mm (in film terms) camera shake is a problem.

Second usage is when you're touristing with a walk-around zoom that does f3.5-f5.6 and you go into a dark place like a church and you want to zoom in a bit on detail.

Third case is for friends and family events without flash (your case). You can get quite good results by room lighting without flash. To get the best results you would have to use an external flash and bounce it off the ceiling. The light produced by the flash built into the camera is horrible but that's what everybody uses

I don't know the 40D but on my D300 the noise at 3200ISO is quite pleasant. It certainly isn't a problem.

As for 1/8000s shutter speed - I have no use for it. If I do a picture of a racing car going past I want to pan and have the motion blur in the background. 1/8000s it's going to look like it's standing still.