To start off, I'd like to say that I think this subject was brought up a little ahead of it's time. To say that there aren't that many GOOD jam bands left seems to me to be a quite ignorant assumption, no offense intended of course. It's just that their are tons of great groups out there in the jam buisiness, but many just haven't attain country-wide or world-wide popularity. Flowmotion, Revolutionary Side Effects, Garaj Mahal, Modern Groove Syndicate, ALO, Mr. Blotto, New Monsoon, just to name a few. It just seems wrong to me for someone to say that the good jambands are dissapearing. Maybe it would be better stated that the POPULAR good jam bands are dissapearing.
But I realize that that is not the question, so I apoligize. Answering the question of who is going to break out on the scene as the next BIG awesome jam bands, my guess is as good as any. ALO seems to be growing in popularity, but sound is not original enough to be huge like SCI or Phish. Originality is likely going to be the main factor in who hits it big. It is obvious that people are getting tired of the same "jam band" sound over and over, and it is gonna' take some guys (or gals) who are really original and talented to get to the top of "the Scene".
Luke