[mawz]

The naming convention is a little odd, but understandable.

The DS2 is a simple successor to the DS, it adds Auto ISO and a 2.5" LCD, nothing else (Pentax missed a good chance to increase the buffer, which is a mistake IMHO).

The DL is a cut-down DS2. Pentamirror Viewfinder (Smaller than the DS's as well), and the AF unit is cut down to 3 point instead of the 11 point unit with 9 cross sensors in the DS, DS2 and D. This is a Canon 300D competitor, while the DS2 is up against the D50 and 350D. All the cost savings appear to be in the viewfinder and AF unit, I'd suspect everything except the viewfinder housing, Viewfinder and AF unit is physically common between the DS2 and DL. Given that one of the biggest selling points for the DS is its superb viewfinder, this is a fair bit of cutting down.

The D is a fair bit more camera than the DS or DL. It's got more control (Hyper programs especially), is generally quicker to use due to having independant controls for most settings while the DS and DL require you to use the menu and offers features that are more important for the semi-pro photographer (Vertical grip, PC Sync, wireless commander mode on the built-in flash, AF-C in all modes, quick selection of focus points and metering modes). This was aimed at the EOS 10D and D100, but is now up against the D70s and EOS 20d, it generally holds it's own against the D70s in everything except buffer size and drive speed, but the 20d is a fair bit more camera in some regards.

Pentax has pretty much the same breakdown as the Canon DSLR's in the consumer/semi-pro market. 1 low-end body (The DL, EOS 300D), one mid-range body aimed at the core of the market (DS/DS2 and the 350D) and one serious body aimed at pro's who don't need more and semi-pros (D, 20d). Nikon covers the same markets with two bodies by putting them in the gaps (D50 in between the 300D and 350D, D70s in between the 350D and 20d). Note that the *ist D is now discontinued, hopefully Pentax will replace it with a worthy body (Frankly, all I want in the D's successor is 8MP, 3fps with a buffer for ~20 L*** JPEG's ISO button so you don't have to take the camera out of a shooting mode to change ISO, and the DS's grip contour, everything else about the D is pretty well sorted. Full-aperture coupling on plain K mount lenses would be nice as well)