@all the people complaining about "underused picks" or "troll picks" or "omg support picks Wukong wtf"... I don't see any sign on the vid saying "I'm Elementz and this is the champ I play most", it's favorite champ. IOW, if you could play this champ every match without getting hard-countered or wrecking team comps, you would.
Nah, Wu's not strong enough for pro play imho. I don't play him but I would think decoy would be easily wrecked by an oracle or pink ward, which would hurt him a lot. But he does appear to be insanely fun. And hey, fun is good when picking your favorite champ. Singed is very very fun too, no wonder Dyrus loves him. 
@whoever commented on Singed not being seen in pro play (sorry, I'm not going to go back and find your comment in 9 pages of raging): he actually was used in a recent tournament IIRC. It took a triple Shurelia to catch him. And I believe the big problem with that team wasn't the Singed but that the rest of his team melted too fast.
If I had to guess why he's not seen more often in tournaments, his weaker early game doesn't do him any favors. Someone who can keep him from getting to the late game until too late essentially makes it a 4v5, since a Singed without farm is a very very unhappy Singed, and a moderately squishy one as well. And without Rylai, his trolling/cc potential drops sharply, further reducing his usefulness.