I have to give the show credit for that Jack recast, it was different than the usual "character leaves for two weeks and comes home with a new face". Unexpected and interesting. That said, I was finally accepting the new Jack (I hated how he was fired and written out as Matt Ashford), and never gelled with the new guy with the new Jennifer.
I didn't know Kathy Griffin was on the show! I love her! I might have to look those scenes up (wasn't watching in '05).
Re: Austin & Carrie's return, et al - Wow what an exciting time! Too bad they ruined it with the Rafe/Carrie Abby/Austin nonce!! And then the next headwriter had John try to sleep with Kristen...ew.