Hantuchova will be one. She's got a pretty big game, great all around, and she's proven against the top players that she can certainly hang with them. With a bit more experience she will start notching off a few more of those close ones, and start coming through with more slam wins too.
The other, not quite sure, but maybe Bedanova. She's gotten a few good slam results already along with some good wins over some of the bigger names. The only thing holding her back at all is the fact that she doesn't really have a big game. If she can bring a bit more power into her game then I think she will make a nice rise up. Krasnoroutskaya is also a candidate who could move up well, had a couple good results at the slams, and I think with experience she can move up well. Nerves may be the only thing she needs to work on. In big matches against top players she didn't produce as much as I would have expected, though she was still under age eligibility so I think she should be cut some slack due to that. She had a great ranking considering the restriction.
I want to throw my two cents in, I cruise the board daily but this is only my second post.
I agree with most of the assesment of Daja, but I somewhat disagree on the power part. Did you see the Seles match, she was matching seles power for power, shot selection for shot selection and she also has a good serve and moves well. She is definitely a sure shot.
The thing about Henin particularly (Clijsters had been consistently lurking for 2 years) is that she came from nowhere, as far as #42 is nowhere (no disrespect meant).
Up until USO 2000 had no really big wins but huge potential, and had pushed top players close. For me that takes out Tulayanova (not that she won't do well, but that it won't be a Henin, more of a Clijsters perhaps?). Same for Krasnouroutskaya, Hantuchova, Petrova. There gonna do things next year for sure, but I'm looking for the really dark horses.
Now if you say to me 'Bovina', then I'm interested or Alicia Molik, cause that would be of similar kind of proportions in terms of surprise.