Microsoft rolls out two-step verification

Over the next couple days we will roll out a major upgrade to Microsoft account, including optional two-step verification to help keep your account more secure.

More info here

http://blogs.technet.com/b/microsoft_blog/archive/2013/04/17/microsoft-account-gets-more-secure.aspx

seems like a lot of companies are implementing this recently, perhaps as a response to the (gawker, I think?) reporter who was hacked last year