As neither are entry-level cameras, I don't think they are going to go head-to-head. They are both aimed at the people who are upgrading, so will probably have lots of the compatible kit anyway and that makes it unlikely that either 'side' will jump ship.
Also the 40D is a lot younger than the D200, so maybe we should wait until the D300 is announced before we start comparing them.
The 40D does seem to be a step forward for any Canon owner, and looking at the specs and price, it looks pretty good.
AJ Purdy have now got the D200 at £799......
