I think I like most of the changes. Wait and see type of thing, of course. But it's almost a completely different game now.
Categories: brilliant. Such a subtle change, but it makes a risk worth a reward if you know your Shakespeare. Viewers will want to see what the $100K question on "ice cream" is too.
New lifelines: I hate to think that 50:50 is going by the wayside, but Double Dip is enough of a "certain" lifeline that I don't think it will be missed too much.
Clock: I'm fine with this. I would have been fine with it if it had been introduced on Meredith's day one. It's going to cause contestants to be in the zone that much more, and the pace should be much better as well.
Not different enough that it should scare long-time viewers, but yes, this is a very different game than we're used to.
EDIT: To Travis: on the Regis version, contestants were allowed to take as much time as they wanted, bar none. Of course, that's within reason. But there was no official time limit. I doubt there was a limit on Meredith's version, because so much could be edited out.