You do not need to play WoW to have an account on the new forums. They aren't WoW specific, they are the replacement for the current Battle.Net forum and so all you need is an account (As far as I can tell, you don't even need a Blizzard game to register) so this does nothing to stop trolling at all, it'll just mean a load of fake accounts being used for posting.
The only thing this does is give information out to the people you may not want to have that information. Teachers in the UK are not allowed to interact with pupils, beyond polite greetings and the like, outside of a school environment with the possibility of being fired if they do. This essentially blocks them from using the forums because of the risk involved.
Why could they not allow you to set up an alias that shows on the forum and links to a list of characters on that account that are on the armory and allow us to pick a character to post as alongside that alias?
Bare in mind, if you have any kind of technical problem you will get asked to post it on the forum. You can phone them and then wait in the queue for ages (which is only going to get worse) or just not bother if you are in a position where you need to remain anonymous on WoW.
I've used and moderated a fair few forums over the years and, though I've never needed to moderate as many posts and users as Blizzard do, any decent forum software makes it as easy as possible for the moderator to do their job. Things like having a page that lists each flagged post with the ability on that screen to delete, ban, temp-ban, edit, visit in context and reply to the message without hunting through the actual thread.
One feature I'd really suggest Blizzard consider adding for their moderators is a way for the system to flag IPs that have had multiple accounts banned so that if someone really doesn't take a hint they can ban by IP for a period of time.
Instead they are implementing a change that only alienates good posters and security conscious players and makes all kinds of new trolling possible and worse, could potentially affect someone in real life