As long as it gets a chance to end on its own terms like BSG did, and not yanked at the end like Caprica and SGU.
Well, in defense of the SGU
finale, it quickly became clear to me that the writers had absolutely no clue where it was going, so it ended at just about as good a point as any. At least it did provide the series with emotional closure, even if it ended on something of a narrative cliffhanger.
But in the case of Community,
I certainly hope that it gets a proper finale. It seems like they would be able to do a lot with that, particularly if they have Abed tear down the last vestiges of its 4th wall. (I'm convinced that Abed correctly realized some time ago that they're all TV characters and has attempted to manipulate his universe accordingly.)