I don't expect many type II diabetics undergoing islet cell transplants. Normalizing sugar only does so much. Optimal sugar management likely reduces retinopathy, neuropathy and nephropathy. It doesn't improve cardiovascular outcomes (i.e. you are just as likely to have a heart attack or stroke with a good or bad overall blood sugar). The single most important thing in reducing mortality and morbidity in a diabetic is good blood pressure control.
Type I diabetics have the constant food / insulin juggling act and low blood sugars they want to avoid. Type II's are not so symptomatic or inconvenienced, even when they need insulin. In my mind islet cell transplants will largely be a type I treatment.