The characters are in 3D for BD, while in DD they were 2D. That means in DD the animations were all hand tweaked series of images, which takes a lot of time and hard drive space. In BD they are 3D models, which take up much less space (this is the reason the install size dropped from 3 CDs to 2) and allows for much more customization and variety of movements. Also, there can be more variety of equipment, which actually looks different on the character when equipped (in DD all large shields looked the same, etc).
Unfortunately, the character models are not highly detailed (possibly to keep system requirements low). They look good in general, but if you zoom in, character feet are not that great.
The game engine being used for DD2 looks quite good, so I doubt there will be any need to cut corners on anyone's feet in the future. <img src="/ubbthreads/images/graemlins/biggrin.gif" alt="" />
