One of our readers wrote in this morning with a followup, and it seems that everyone who had issues is being granted a 15-day playtime credit on their account to make up for it. Half a month across the board is a pretty substantial credit, especially considering many of the people we've heard from were only locked out of their characters for a couple of days. I'm sure we'd all prefer there was never a problem to begin with, but this is a pretty generous compensation if true. I was impressed when they gave everyone a three day credit awhile back.
I said 'if true' up there because we haven't seen much on this in an official capacity. As far as we've seen, there are no announcements or notices about it, just the e-mails going out. I have no reason to believe this is a phishing attempt though, the e-mail specifically states no action is required on the part of the user, and asks for no information. It seems (to me, at least) that this is legit, and Blizzard has made a pretty big step in patching up the mess.