They did this last year... he calls again regardless of whether you had the first interview and basically just makes sure you're still interested before making an offer. So, if you got this, congratulations. You're almost certainly in.
But, if, like me, you didn't, then you missed the first wave of WL admits and probably just saw your chances of admission fall by half. I hate to say that, but if this is going to be anything like last year its true.