It does look like a burn to me, however, I'm not a vet. I've had a snake that burned his belly, though, and it will definitely require a vet's assistance. Mine had to have his belly scraped, then rinsed with saline and silver sulfinadine (sp?) cream applied. I also had to soak him once/day for 30 minutes, rinse with saline, and apply the cream for about two weeks. Also had an additional daily saline rinse/cream application (without soaking). So if it is indeed a burn, it is going to take some time on your part for the next couple of weeks. But I really want to stress the importance of taking your snake to a qualified vet--when I called mine when I first saw the problem, he hurried into his office on a Sunday to take a look at him, so apparently it was fairly important that it be taken care of quickly.

Best of luck! If it is a burn, and it's properly treated, it should heal up nicely. There may be some minor scarring, but otherwise the snake should recover fully.