What ElfiePoo ^ said.
If you pay attention to your post-surgery diet, you may end up dropping your diabetes meds. I was diagnosed Type 2 a couple of years ago and put on Metformin and Amaryl. As I dieted during the ramp up for my banding, I was taken off Amaryl due to good blood numbers, then my Metformin dose was cut in half post-surgery, and as of last week I am now off all diabetes and blood pressure meds.
Banding is not a magic bullet - you still have to eat right, but the band gave me the edge I needed to get the ball rolling.