The jokes aren't great but I like that the blonde isn't the typical vapid rich-girl stereotype. And the two actresses have a pretty good chemistry onscreen, which is helping to keep my attention (in addition to Kat's well-stuffed uniform).
I'm pretty sure I read somewhere that CBS has recently decided to give them a full order of episodes for the season, so hopefully there'll be enough space (and feedback) for the writers to fix the problems.