Fairly high, actually. The main goal of just about every active mod is to port to Warband, at the moment.
There's also some great ones in production for Warband as well.
One mod to look out for though, is The Last Days of the Third Age (LotR)
It's only for .808 of the original game, but they're porting it to 1.011 of the original, and expect it to be out sometime soon.
(next couple of months)
hmm... we'll see.