But if that were it, that wouldn't qualify the fourth season of 'Til Death as some sort of weird, outre comedy. It would certainly be more interesting than what the show had been before, but not necessarily worth seeking out. Perhaps realizing that the role of Ally (Joy and Eddie's daughter) had been played by four actresses over the course of the series (including Krysten Ritter!) while the role of boyfriend/fiancee/husband Doug had been played by only Sharp, the series embarked on an astoundingly bizarre story arc: It had Doug realize he was a character in a sitcom whose wife kept getting recast, then sent him to psychotherapy to make peace with this fact. - Todd VanDerWerff at The A.V. Club Blog
I've always enjoyed watching how TV shows take their impending cancelation. The last season of NewsRadio is in very off the wall as well - to an unwatchable extent, in my opinion. I think my favorite reaction to a show's death is that of Arrested Development. They threw in little lines here and there toward the end of its final season but they never destroyed the show. At no point did the Bluth family ever find themselves in outer space.
It's unclear to me whether the actions of 'Til Death, NewsRadio, and others constitute jumping the shark. Part of me says that they clearly do. These shows are making insane attempts to draw attention - VanDerWerff notes 'Till Dealth's "aggressively unfunny stunt-casting." Yet these shows are well aware of their impending doom; in some cases they've literally already been handed a death sentence. So if you're done with, can you really jump the shark? Jumping the shark seems to imply a sense of failure on the part of the people making the show. They've become desperate - either for attention or ideas. The jump is the turning point between a good show and a failed show. Yet, these are shows that have already essentially failed. They aren't bad because of some "shark" moment. They've just run their course, or in some cases have never been on course. Their crazy antics aren't really a desperate attempt to keep the show relevant. They're just a way to pass the time as the ship slowly sinks. So in that regard, I'm not sure it counts as jumping the shark. It's more of a stick-it-to-the-man kind of thing.
Regardless, 'Till Death sucked.