To be fair, the OP asked for advice on Canon models, please refrain from using this as an opportunity to advertise a sale of your Nikon.
CanonRumors.com is rife with news of price drops and the expected release of the 50D. The best thing you could do is wait for it to be released. There is a prediction that it will feature the 51 point internal focus.
The 40D is a superb camera and it is probably worth anyone becoming more adept at using manual focus.