@ RShara - thanks, I'd wondered about this as well.
@ Horatio - As near as I understand it, a binary star systems is theoretically possible, but also short-lived. The orbits between masses begin to decay and the larger star (vampire star) eats the smaller mass.
As far as habitable planets within a binary system, I thought it was basically impossible, but then I did some research:
http://en.wikipedia.org/wiki/Binary_star#Planets
Turns out that (supposedly) 50-60% of binary systems are capable of supporting life, given that there is a terrestrial mass with the right make-up and orbit.
So yes, your idea is plausible.
I learned something new today...