The Imaging Resource has a detailed account of the changes of the Sigma DP2 as presented by Sigma at PMA 2009. There are some small and some interesting changes made. Imaging Resource goes through the spec-sheet line by line!
RAWsumer reviews at the Compact Reviews Organizer
CANON: G11 S95 G10 G9 S90 SX1is
PANASONIC: LX5 LX3 LX2 FZ50 FZ100 FZ40/FZ45 FZ38/FZ35 FZ28
RICOH: GRD III GRD II GX200
SIGMA: DP2 DP1
NIKON: P7000 P6000
CAMERA DIARIES: Panasonic LX3 Canon G10