Yes I agree on that it's not a good thing Canon users have to spend money on a new battery grip, batteries and memory. Though, Canons switched to SD to make room for the 3" LCD and the memory will also be a bit cheaper. I don't think the memory is a big problem. The new battery grip is said to have a better design and the batteries have longer life.
I'm not sure why Canon not has built in IS. But my guess is that the price would go up and they want to keep it pretty low. Many beginner photographers never buy a second lens.
It makes it the most advanced entry-level SLR because of the Live view which supports all kinds of AF (the only camera in the world that does this, not 40D or even 1D mkIII supports that), the menu system is from the 1D. 4 fps and an improved 9 point AF. Uhm, is the K200D even out yet? Weird to compare them. I HIGHLY doubt that the noise reduction will be worse than on the 400D. That would be stupid.

I'm still convinced the 450D is the most advanced entry-level camera. But that doesn't mean that Pentax's next camera won't be better (but they gonna have to work hard to beat Canon). I'm talking about today.