I'm not a big fan of the post-credits scenes thing.
And I don't really care if they have something at the end that could be used to lead to the 3rd movie, as long as the story of STID is wrapped up. No cliffhangers, please.
NO NO NO! Cliffhangers. PLEASE!!! Means we get another Trek by the Bad Robot group.
If it makes money, we will get more.
Having or not having cliffhangers has nothing to do with it.