Pretty much - I just did it two days ago. They won't just unlock it - you have to provide a good / convincing reason. Traveling abroad worked fine for me - and after 30 minutes on the phone (most on hold) I got the unlock code. Worked like a charm.
PS. I got my w580i on a pay-as-you-go plan .. so it may be different if you're under contract - but I understand that in general if you're ATT customer for over 90 days this isn't an issue.