For a while now the mantra/easter egg tagline in Community has been "6 Seasons And A Movie". Now that they've hit six seasons (despite NBC's best efforts to get the series cancelled), I would say that a movie could be likely at this point. For me, I personally would prefer for them to just move on to season 7, especially after how amazing season 6 was, if for no other reason than the fact that 12+ episodes offers significantly more content than a movie would.

That being said, if Dan Harmon and the crew decided to make a movie I don't think they'd do it unless they had a decent budget, a story worth telling that everyone liked, and the ability/reason to do things that they otherwise couldn't within an episodes' time and content restraints. And given the general response from the crew, the reception for this past season, and a number of other factors, I'd say that it's probable that there will be a seventh season either way this pans out.