I thought act one in "Ocean's Three and a Half" was a step back in the right direction with some rapid fire/unexpected jokes, but it dropped the ball in acts two and three. And this episode wasn't exactly back to high form, either. There were a few laughs in it, but yeah, the "magic" of the show seems to be lost, or at the very most, comes back in spurts (whether it be for a few inspired jokes or even a full episode every once in a while, such as "Stewie Loves Lois") and then vanishes again.
Interestingly, Richard Appel wrote this one, and he was responsible for some of the best episodes of The Simpsons from seasons 7-9, including the excellent "Mother Simpson". What a step down. Though like always, it's hard to know who to blame; Appel himself for a bad day, or the writer's room that changes something potentially good into mediocrity.