To be honest, I still think it's something of a longshot for the GOP to get to sixty senators next November (or 59, plus Ben Nelson, who presumably still would vote to break the filibuster), but it's not unrealistic, either. Again, Howard Dean as the Dem nominee would bump up our numbers nicely.
Even if Republicans fall short of sixty, though, I'm pretty confident they will have enough to sustain the "nuclear option," if it comes to that.
Honestly, I'd be very surprised if - even with Dean on the ballot - the GOP could get to 60. Too much would have to go right, IMHO. But I do agree they'd probably have the nuclear votes, if the Dems were dumb enough to once again not learn a lesson.