It appears that feats like TWF, Spring Attack, etc. are being re-dedicated and siloed off into classes. That might be good for streamlining difficult decisions for newer players, but it is indisputably bad for player choice overall.
But it is almost certainly better for crafting rules for high quality two weapon fighters, high quality spring attackers, etc.
Consider Spring Attack in 3e. Sure, anyone could take it. It was actually GOOD, though, only for a few types of characters. A rogue could kind of take it, but most didn't because there were better choices and giving up iterative attacks really sucks. A fighter could kind of take it, but until the PHBII it was almost always a bad option (barring spiked chain cheese) because giving up iterative attacks is murder on a fighter.
It wasn't until the Scout that spring attack, used for its actual intended purpose of springing forwards, attacking, then ducking out of reach, was a good idea. The class itself had to be designed around giving up iterative attacks in order to spring attack instead.
I personally favor moving Spring Attack into class feature territory, with the caveat that as newer classes come out, some will probably cover similar territory. You know, if spring attack is a rogue ability now, and eventually a Swashbuckler is released, there's some logical crossover between the two.
I don't quite think that two weapon fighting should be automatically off limits to everyone but rogues and rangers, but I'd be shocked if it really was impossible for other classes. The fact that most of the neat two weapon fighting abilities show up as Ranger class features doesn't preclude other classes from using two weapon fighting as well.