maybe during the induction phase of South Beach, when you're only eating protein, some fat, and some veggies. after that phase, however, you slowly add in things like starchy carbs, legumes, and sugar, making it quite obviously different than paleo.
paleo is far better and more sustainable, IMO.
I was doing South Beach before I discovered paleo, and switching to paleo was a very natural transition. The first couple weeks of South Beach are pretty much the same as paleo. You are avoiding refined carbohydrates and other high glycemic index foods. The main difference I have noticed is the emphasis on grass-fed beef, wild fish, etc. That might be a part of South Beach that I didn't notice, but it wasn't emphasized as much as with paleo.