Kaaya doesn't look as hot and Coopa doesn't look as cute. (she doesn't really look like she's aged, though) Those look like they might be temporary getups, though.
At least Fatina still looks great. That's what matters the most as far as character designs are concerned.
Edit:
High resolution scan, where?!
I wouldn't be surprised if I never got one. Too many of these go unscanned. ;_;
Edit #2:
http://www.druaga-anime.com/gallery_art2.html
http://www.druaga-anime.com/gallery_ill.html
Looking at some of these, it looks like the character designs were improved quiet a bit from their earlier concepts.
There's a small chance that I may never have watched Druaga if Fatina had looked like that. (small... Fatina was only one of the selling points; I mostly watched because people loved the first episode)
This would be on topic for the first season's topic, but its on topic here too, and that threads going to be pretty much dead in a few weeks, so...