Jupiter065 said:
Seems like an unbelievably tasteless marketing ploy to me.
I've had similar thoughts, as well as thinking that if this much attention was given to him while he was still alive, maybe things would have ended differently. Of course it seems we know more about him after he's passed than we did when he was alive.
That said something CAN double as a memorial and marketing tactic, in the case of WoW, if he really was a player it's not unreasonable. Honestly though if I was Blizzard I'd be a bit more subtle than people's other ideas. If I was the guy who was going to make his memorial, I'd put an NPC standing around one of the auction house areas named after his character, since he allegedly liked to troll the trade channel (and I imagine Robin Williams was a hugely amusing Troll). People on the server where he played will probably figure it out, so it will get around, but it will be a mystery to begin with.
This would be a tribute to Robin Williams in WoW, as opposed to another celebrity parody like Haris Pilton (who I've actually wondered about playing WoW, given the reference). At the end of the day celebrities are people too and kill time doing the same things the rest of us do. I'm wary when people claim to be someone famous online, since I figure most keep a low profile, but it is possible.