Jill definitely has interesting implications for the future of the series. I'd hoped that she was going to try to shoot Sarah, and Chuck shot her first to get his "First Kill." Man, that would have been great drama, there (I don't count Uncle Bernie and Phil as "kills" in that episode. Bernie had a heart attac on his own, and Phil would have probably gone out the window either way). But I REALLY want to see where this is going. Is Jill going to return from FULCRUM? Was the part she'd said before about wishing she could get out true and she goes on the run from BOTH?
I still get the feeling she turns up again eventually to return the ring Chuck let her keep so he can give it to Sarah.
And agreed, LOVE Casey, especially all the completely random and seemingly out-of-character things that the writers come up with for his background. It's absolutely hilarious seeing things like the bonsai tree, his obsession with quiche, and randomly learning he was a choir boy and has perfect pitch ("What? Do you think I was hatched?"

). That's why I hope we never learn TOO much about him, because it gives them less room to come up with crazy things like that.
Although I'm going to say it now: Casey's mom HAS to be Leslie Easterbrook in full-on Callahan mode:

She's a LITTLE young if we assume Casey is as old as Baldwin (47) but TV/movie magic can fudge it.
And it would be outright HILARIOUS if Casey's dad turned out to be a total liberal hippie anti-Casey. ESPECIALLY if they got R. Lee Ermy to do it playing against type (even better if they hyped "R. Lee Ermy as Casey Sr.," but don't show him at ALL in the previews, so it's a total surprise when he appears). That's just the sort of joke I can see them pulling.
Whatever financial cuts they had to make for Season 3, it sure wasn't in their casting budget:
Armand Assante
Brandon Routh
Kirsten Kreuk
Angie Harmon
"Stone Cold" Steve Austin
I still hope they find a way to bring in Shatner and Hasselhoff. Shat would be absolutely HILARIOUS with the way he can make fun of himself, (there's LOTS of Star Trek connections on the show, too) and with all the 80s geek references they HAVE to bring in the Hoff. And John Larroquette NEEDS to come back.