Some players will leave, like every year. I believe I was counting and we are in a similar situation numbers-wise. We only have 14 graduating seniors, and I believe we have around 81 or 82 on scholarship, though it's hard to count that, so theoretically, we should have around 18 spots to fill. We'll sign a full 25 though, and we'll have attrition take care of the rest.
Nick Saban has had this same problem the past couple years, except he's even more ridiculous about it. I believe he still has about 4 or 5 to cut before camp. That's been his problem. He hasn't had natural attrition take care of players for him, so he has had to put a few on medical hardship (something I didn't even know existed) and tell a few, like Alonzo Lawrence, that they no longer had a scholarship. Apparently if a player is hurt, you can put them on medical hardship or something along those lines and have them sit out.
Basically Saban has taken it to a point where he brings in a load of talent and then only keeps the best of the best, telling the rest to hit the road. It's similar to the way they used to do it in the 60s, where they'd bring in 70-90 players and then run off the ones that weren't any good. He's doing it on a smaller scale and working around the current rules, but he's loopholing the crap out of the NCAA and their scholarship limits to make sure he can trim the fat.
Unfortunately, we can't do that because we can't afford to burn bridges with schools. With his reputation, he can do what he wants and still go out and bring in talent.