Good mechanics are good mechanics, no matter where they come from. Even if it is WoW.
I guess if they want to please the anti-WoW people though, they are going to have to go out of their way to keep anything WoW uses out of D&D, no matter how good it is. I'll help them out:
They can't use levels, because WoW has levels.
They can't use classes, because WoW has classes.
They can't use races, because WoW has races.
They can't use magic, because WoW has magic.
They can't use random numbers, because WoW uses random numbers.
They can't use words, because WoW uses words.
Seriously people. Of course 4th edition is going to be alot like WoW. WoW is alot like D&D. It probably wouldn't even exist if it wasn't for D&D. You could probably find at least 50 things in even -Basic- D&D that are like WoW.
-Who cares- if the dragon's default attack routine looks a bit like Onyxia's attack routine? Is it a bad idea to give a guideline on how a dragon will usually attack? Of course it isn't. Is the attack routine wizards came up with a believable attack routine for a dragon? Sure looks like it to me. What the heck is there to complain about? A good mechanic is a good mechanic no matter where it comes from.