I feel like ever since UU was "released" that I've seen many more UU teams around. Or maybe I just didn't pay much attention before. On a side note, I got absolutely raped by a belly drum/E-Speed Linoone the other day. TBQA I completely forgot that Linoone got Extremespeed from an event until it was too late... It almost OHKO'd my Uxie with E-Speed (And I'm pretty sure most carry Shadow Claw and/or Return...)
As for common pokes, I see Jellicent, Latios, Garchomp, Gyarados, and Haxorus quite often. I think it'd be "fun" to make usage statistics for random wifi matches...