If America does get a poll, instead of voting for something kinda good like Ditto how about we vote for something REALLY good like Technician Breloom. (It's #4 in PO's DW for a reason)
Both solve problems in OU, but Breloom stops a LOT more than Ditto could ever dream to. It's comparable to Scizor with a 75 (2 hits) to 187 Base Power (5 Hits) Grass-type attack and can actually OHKO things like Infernape with it's Proirity alone after one Swords Dance and it of course turns top Pokemon like Ferrothorn, Rotom-W, Tyranitar, & Politoed into a free Swords Dance due to Spore/fear of it's STABs. Pack a Pursuit Pokemon for all those Psychics & Ghosts that are faster (Breloom & Scizor just Brofist all day) and just go to town. I guarantee all the Excadrill bitching will stop when Breloom is released. Unless you actually play Dream World, you have no idea how much of a (Un)Holy Arrow Technician Breloom's Mach Punch is. To put it into some kind of perspective, at +2 it's basically a STAB Close Combat with +1 priority and no downside coming from 394 Attack not even factoring Life Orb in.
Aside from lack of team preview & general awesomeness, Breloom is one big reasons Max HP/Def Espeon is #10 in DW OU. If Breloom uses Spore, you better be packing a Dragon or a Ghost.
Ditto was only good in early DW OU because of things like Contrary Serperior, Speed Boost Blaziken, Swift Swim Kingdra, & Garchomp running around. Without any of that in OU, Ditto's sole job in OU is scouting & revenging Dragon Dancers. That is all Ditto is good for and there are better Pokemon to do it with.
For instance, Cloyster, a Pokemon that's been a little brushed aside as of late. Bold Cloyster, yes Bold, can OHKO Max HP Multiscale Dragonite with Icicle Spear with no Attack investment & survive a +1 Outrage with no Defense investment. That's right, 4th Gen Cloyster; Bold, 252/0/0/0/252/4 Cloyster completely counters the #1 boosting Dragon around, doesn't even need to run so much as a neutral attacking nature. Haxorus is almost the same story. Too bad most people don't know this as they're too busy trying to find a Pokemon to revenge them with like Ditto instead of completely countering it so you don't lose a Pokemon in the first place. And don't even tell me Cloyster isn't more useful to a team than Ditto. (Assuming that Team isn't stall, cause Ditto's actually a godsend to stall teams...Haze T-Wave Murkrow kinda outclasses Ditto though since it can do something to Defensive boosters...)
Scarf Ditto just isn't that good in OU. He copys a +2 Thundurus? Good for him! Gastrodon & Ferrothorn would love to meet & KO/T-Wave him! Especially considering he lacks a Life Orb. Oh and that Thundurus is still alive btw.
The thing is, most teams do carry a counter for their own sweeper. Especially OU teams since they have to prepare for that same Pokemon being on the other team as well. So in that sense, nearly every team has a Ditto counter or at least a check.
Any Dream World player of any merit will tell you that Ditto is 60% hype & 40% action. He's good but in the same way that Weavile was good in 4th Gen. He was great in the begining but since the Pokemon he would be the best counter for ALL got banned/don't exist yet, he's not that good.
So yeah. If America gets a poll, don't vote for Ditto, you will be sorely disappointed. Vote for Technician Breloom or Lightning Rod Zapdos. They're actually good. And start using Bulky Shell Smash Cloyster, it's a dick even without Smashing.