I must say,  the forum is growing very fast and the innovations are been appreciated by those who truly understands the uses of those additional features. Guessing theymos next option now is to look into enabling self-moderated thread on meta and giving us an official guidelines to leaving trust feedbacks. These are the two hottest topics right now and doing justice to them will go a long way.
I must say the implementation of the merit system has the highest impact on forum (from my view) and that's my fav of all the innovations and my least is the minor selfmod enhancement. (although it's too early to judge so I'll give it sometime)