TinoP:
I think this thing is a smart marketing gimmick from canon. They made the body toooo small and then they sell this extension for extra £ 100. They should come as a free upgrade
I've got a 350D and without the grip it does feel very small. My 30D in comparison feels comfortable without a grip and I haven't found it necessary to have one fitted.
I don't think it is a marketing gimmick. This isn't to everyones liking, however if you're serious about photography and invest in the likes of a 1D series, you'll find that the body and grip are somewhat part and parcel of the camera.