*Owens is part of it, yes, but there's other things as well. A lot of people forget that Trent was part of MVP discussions for a good chunk of last year before he got the concussion. He's not only healthy now but has a veteran (Fitzpatrick) to get advice from instead of that idiot JP Loss-man.
*Jason Peters is now gone (trust me, good thing.) and they've completely retooled their O-line, which means no more horrendous pass protection and possibly better run protection for Lynch/Jackson.
*The Bills now know that Jackson is as good as Lynch in most regards, giving them a 1-2 running back system that should go for 1000 yards at least for both backs.
*No more stacking the box every play on defense now that the Bills have 2 fantastic receivers that will draw D's attentions, giving lots more room and not as much need for BEAST MODE every play.
*And obviously, say what you will about TO but he IS a future hall of famer and one of the best WRs on the market. Defenses will either have to double team him or Evans and whichever one is open will be thrown to, it's nice having more than just 1 receiver on a team.
I have a whoooole spiel on why "TO IS A CANCER THAT WILL DESTROY THE BILLS" is a stupid thing to say, but that's another post entirely
Basically the Bills had almost all of the pieces in place last year but needed a good receiver and a new O-line (as well as fewer bites of the injury bug) to maintain them. Obviously most of this means I think Lynch, Evans, Owens, Trent and Jackson won't get injured, but that applies for every team, I think.