yeah, its a good thing to have a roommate to go in with you. Just make sure you guys don't be too strict with each other and compete with each other- I've heard several stories where "roomie dieting" goes in the wrong direction.
My MIL and Aunt recently both started a diet plan together. They eat all their meals together and live next door to each other. They are doing great with 16 and 16.5 lbs. lost. They are great support for each other. I'm sure yours will work great too. Congrat's on getting started.