Here are details from the TSA: Changes to Prohibited Items List (PIL) - March 2013

It's still substantially more restrictive than one might think if one were only considering blade length (no longer than 2.36").

Blade wider than 1/2"? Not allowed.

Blade locks "firmly"? Not allowed.

Knife has "molded grip"? Not allowed. (Good luck on getting a clear definition of what constitutes a "molded grip".)

To their credit, if it allows one to take along a small Swiss army knife or Leatherman Squirt, well, that's at least some improvement, IMHO.