I'd guess at Tim vs. Judy/Jennifer.
Although Gregg is...Gregg, he's got a second Latin dance and a lot of potential for memorability with that dance, and I think he'll get through.
I think Tim will struggle because he has the Waltz, and even if he's better at it that the Cha Cha Cha, I don't think it will be particularly memorable. That leaves Judy or Jennifer, and while Judy isn't the biggest of personalities, the Anton factor might get her through, whereas Jennifer has a new pro and is one of the lesser know celebrities, but perhaps a bigger personality and likely to dance better at the weekend.
EDIT: I also think Sunetra will struggle with votes, but I think she'll be high enough up the leaderboard to get her through the first week.