I had seen Xcell-center website for the first time a few days ago. Their procedure (I believe) uses your own stem cells, and therefore may not require the same lifelong immunosuppresant drugs as the islet cell transplants which are being done on clinical trials at various medical centers throughout the US. Like you, I also don't trust the Xcell treatment because they claim to be able to treat just about every major disorder. (It doesn't matter anyway because I'm sure insurance wouldn't cover it and I don't have a spare $30,000.)
The outcome of the islet cell transplants done here in the US hasn't been so great yet. After five years, only one in ten patients was still free from requiring insulin. The procedure requires a lot of immunosuppresant medication for as long as the transplanted cells are still active as well as a great deal of time, dedication and commitment on behalf of the patient. It often requires two or even three transplants in order to take, and the centers require you to be seen once a month for a year after the transplant procedure begins working. The immunosuppressant medications carry considerable risks as well. Overall, they don't recommend getting a transplant unless your diabetes is pretty much uncontrollable. Specifically, they are looking for diabetic patients who suffer from a high degree of hypoglycemic unawareness.
I do believe, however, that a real breakthrough is on the horizon. We should continue to support and fund this research, and of course, we can hope and pray.