RAW straight out of the camera should actually look a bit worse than JPG (when viewed on a "normal" LCD monitor)
It has no sharpening or anything else applied. When you view it in CS3 Camera RAW, it will typically auto-apply the settings recommended by the camera I think, so they will look almost identical.
The strength comes in when you do some PP, like the "fill light" or "recovery" in CS3. As well as the greater tonal range because of the 12 or 14bit sensor. (450D also has 14 bit sensor).
Also the ease of white balance adjustments.
Thanks for the heads up...............