And? Just because it's Steam doesn't make it any more significant than the other recent hacking targets. I don't let Steam remember my debit card information anyway, and a password change is no big deal.
Besides, anyone that does actually lose their account - if it happens at all - can get it back within a couple days if they have a physical copy of any game on their Steam account. It could take longer if they don't, but a friend of mine got his back without a physical copy.