I've met many silly people in WoW, but to be quite honest none of them have really stood out as a Noob with a capital N. Perhaps I've been lucky? The only ones I can really remember are the level less-than-10 in Tirisfal Glades that decided hitting my friends level 60 human mage was a good idea (she hugged him & one-shot him into oblivion) and the silly person that kicked me from a Botanica PUG because I mind-controlled the Mender. You know, the one that can give an insane half-hour +spelldmg buff? He didn't approve of the casters in the group getting that buff.
Neither of those were terribly noob-ish though. The less-than-10 was more than likely a newbie to the game and had no idea that flagging yourself in the kiddie pool area is a bad idea (especially around the Scarlet Monestary) and the Botanica-jerk later half-apologised by saying he didn't realise the buff lasted that long. What makes me remember them isn't so much what they did as making fun of them in guildchat for several days after each incident occured.
To me, being a noob is more when you know something isn't right and people keep telling you something isn't right but you keep right on doing it anyway. Like a melee hunter, to use a cliché. Thankfully, I have yet to run into a noob like that. Knock on wood!