The Jags should be on the rise. I don't think they'll win the division or anything, more likely just challenging for the playoffs and finishing in the middle somewhere. But they'll cause some losses for the rest of that division this year.
I'd go Titans > Colts > Jags > Texans. Colts are going to be much better this year with Ryan but I don't like their receivers. They have one guy and a bunch of question marks and young options. Only way they win that division is if their defense plays great and the DC they hired is a guy I've always been underwhelmed with. Reason I mention the defense is because their best weapon on offense is their RB and to properly utilize a RB across 17 games requires a defense that has you in shit.
Tannehill gets a lot of flak but he's a lot tougher than people credit him for. He took a hit with his top weapon being traded but they're a run game and defense team anyway and I like the possession options they added in Woody and the kid from UCLA they drafted late. So I think the Titans remain the top team in that division.
I'll be rooting for Lovie and the Texans this year in that division. I think Lovie's one of the true good guys in this league. Texans front office sucks ass but Lovie just had a pretty good draft and if he can make some noise down there in Houston this division gets a lot more interesting.