To me it seems this new UU consist of all the old BL Poke'mon plus some of the commonly used old UU Poke'mon.
And NU is the old UU list plus Medicham and a few other wtf Poke'mon. NU seems most promising.
Yanmega in UU doesn't really affect me personally because I don't think its going to really affect that metagame too much.
But those are my thoughts.