I've been hacked twice in 2 years - both times the GMs restored everything minus enchants etc back. A lot of my alts were deleted and I didnt bother trying to get them back either.....I mean who cares about a warrior or a rogue anyway lol.
After completely cleaning the infected machine (which was my little used laptop) by installing linux over windows I realised as had been stated before that the scammers could use brute force. I now obsessive compulsively change my password after each wow session on my main accounts, even if I'm only logging out for a few minutes.
The account data is all in the Firefox browser cache so it doesn't take long in the retrieve password screen on wow.

By the way the keylogger was really easy to get and loads of wow players got it back in November 06, it was an advert on the alakazham website which downloaded the logger.