I mentioned the 1000D a few daze ago in a post.
As far as I know, it's not a replacement for the 400D - it's a step down.
It's cheaper, lighter (more plastic) and has lower specs all round.
Canon makes 4 series of SLR cameras:
- the unit-series, such as the film EOS 1 and EOS 3, and the digital EOS 1D and EOS 5D. These are the 'pro' cameras $3500 - $12,000.
- the tens-series - the digital EOS 40D is the only current one at the moment and these are the semi-pro/serious amateur cameras - $1500 (Cripes! I paid $2500 a year ago! The price drops means the new 45D? 50D? is on it's way...). In the past there have been others (30D etc) as well as film cameras (EOS 30, EOS 33 etc)
- the 100-series - the 450D, the film EOS 300 etc The normal amateur range - $500 - $1200
- the 1000-series - the film EOS 3000 ($200), which is little more than a plastic semi-disposable SLR. The 1000D is in this category.
Having said all that, give it 6 or 12 months until the price drops by a half and I might get one myself as a spare camera that I won't mind dropping onto concrete or leaving in the car... - I ain't gunna do that with my 40D!!!
Have a look at
http://www.dpreview.com/previews/Canon_1000D/