I oppose it.
I can certainly to see both sides; I understand that from 90 - 100 people will have to learn to play their class.
I also understand that it will probably make the game a lot more healthy, with new players/old players/people who want to experience cool new content with friends coming back to give it a try.
However, I *personally* think the 1 free 90 with WoD was enough; understandably, Blizzard did it so people would not buy more expansions. A valid argument, but I really don't think this'd be widespread, and if they made it so that you had to do it on an account with an existing (at least 60 or so) there would not be a problem.
Unfortunately, this to me feels like profiteering, and while I understand the reasons for doing it, it doesn't sit well with me. I simply feel that if you havn't leveled from 1, like almost everyone else, that is just isn't genuine. It "cheapens" the experience. I don't like leveling, but the gratification and hardwork when you get there is worth it, and everyone recognizes that you put work in. Now there will presumably be a lot of 90's/100's running around, all achieved by basically how much you can fork out.
Call me stupid but I just can't agree with the notion. Logical reasons to do it stand, but personally it feels sly.