Since a lot of people like the old smileys, wouldn't it make sense to allow people to choose which set of smileys they want to use (in the form of a customization setting)? This is assuming, of cource, you're going to implement the new group also once you re-implement version 2.0. You probably thought of this already, and if not, I think it would probably be the best way to settle all the commotion over the smileys.