It's natural to want a sequel. You get involved with characters for 90+ minutes and you want the story to continue. Movies usually have a sequel hook, anyway. The question really is if we'll get the sequel we'll deserve or something like Cars 2, which seems like a comic book adaption/Saturday morning cartoon episode. I mean, I love the Men in Black movies, but the second one was far inferior to that cartoon adaption. The third was an improvement.
I will say, half of those films deserve a sequel, The Chipmunks doesn't. That one's for money. Wreck it Ralph is about Fix-it-Felix Jr. There's a built in sequel right there (maybe we'll get more involvement with Nintendo this time, so we won't have pallet swapped princesses covering their faces). I'm not too happy Smurfs 2 has them come back to our time, but the plot actually sounds slightly better (Gargamel makes an evil army of clone Smurfs). I dunno about Hotel Transylvania 2. I liked that movie, even with problems with script and too much Adam Sandler. I guess there's something to Dracula's daughter being in love with a mortal, leading to the inevitable of him dying, and losing him forever until they turn him into a monster... but knowing them, they'll go for something not half as deep as that.
The funny thing is, to the far future the only Dreamworks sequels I see are 2 for How to Train your Dragon (one in 2014, one in 2016) and one for Kung Fu Panda (2016) (unless you count the Penguins of Madagascar the movie... and SO HELP ME, they better keep cartoon continuity with that).