When the 60D comes out, then the 40D will probably be "officially" discontinued.
I will be purchasing a 50D soon, will be my first xxD camera, did think of the 40D, but I may as well go for the newer model. Did consider waiting for the 60D, but MIGHT not be till January next year, maybe sooner, either way I'm happy to settle with the 50D.
Also, the extra 5MP is also an attraction. I know people will argue the difference between the 40 & 50, but hey, the 50 is a newer model, so may as well go for that one right considering I have been using an "antique" 350D the past few years.
I can see however, that the difference between the 40 and 50D is tiny to make itworthy an upgrade for 40D users.