My understanding is that the term "cure" is thrown around a little too loosely... I don't think you can ever truly reverse it BUT you can manage it very effectively. Like another poster, I have yet to hear about one case where their diabetes became worse on a primal diet. From a biological standpoint, it's very plain to see that this diet would have unbelievably good effects on Insulin Resistance as well as blood sugar normalization.
I would say that the primal lifestyle (not just the diet) is the best way to manage Type 2 diabetes!
Disclaimer -- I'm not an MD but I DO read a lot ;-).
Living the primal lifestyle and loving it! On a constant quest of optimal health and living life to the fullest :-).
You can have excuses or results -- not both.