Dervish Dancing Magi have been the most common builds (frequently using Shocking grasp intensified with metamagic reducers)that I hear of online and see at the tables for as long as I can remember them being discussed.
The only conpetitor for most common build would probably be a debuff stacking build, whip, prehensile hair, enforcer etc.and this one is a distant second in popularity at best.
They may change the leagilty (and probably will based on the other feats) but the combo is now legal and always has been.
Disclaimer: There are infinite ways to build and play your character and I am not implying that these builds are better and certainly not the true way to play. I am just stating that from my experiences it appears that most players have thought that Dervin Dance worked with spellcombat for quite a long time.