The bosses in the DLC packs were a lot better than the main game's. Knoxx and MINAC especially, because CRAAAAAAAAAAAAAAAAAAAAAAAAAW is a cheap bastard no matter how you look at it. Goddamn maggots.
EDIT: IGN has made all of its character preview articles now:
http://pc.ign.com/articles/121/1219414p1.html Zer0
http://pc.ign.com/articles/121/1219322p1.html Maya
http://pc.ign.com/articles/121/1215312p1.html Salvador
http://pc.ign.com/articles/121/1219370p1.html Axton
Maya and Zer0 look amazing, Sal still seems awesome, and Axton has good potential. I just hope Axton gets enough personality to stand out among the other three.