Yeah, I agree with you there.
Anyway, for a better comparison, I think it should continue forever like Pokemon has!! ^_^
Meaning, in my opinion, Futurama should stay true to its main storyline, while at the same time change some things or add new touches here and there, while still at its heart being both the emotional and hilarious series we know and love.
I don't mind the way they sorta changed some things about the series, with the execution of BBS and how that played out. I still enjoyed the movie a lot. Because for me, it doesn't change the episodes themselves, only how some of the things happened in the Futurama timline (which is kinda what makes me confused about the movie, and how it ties in with the series). ^^;