Where do you think the first big big regenerative medicine breakthrough will come from?

Has it already come in the form of Claudia's trachea?

Honestly, I think a huge breakthrough has already came in the field of regenerative medicine in 2008 when a bronchi was bioengineered using a patient's own stem cells and a cadaver's trachea (done by Dr. Paolo Macchiarini [University of Barcelona, Spain] and colleagues). It's really pretty amazing work, and has been successfully repeated in other patients. For more details on it, check out this article I wrote: http://www.independent.com/news/2010/apr/17/engineering-organs/