AFAICT, Jepsen has been more of a seagull [1] than anything. The reality is... she's been a high profile participant in a series of short-term, failed endeavors -- from OLPC, Pixel Qi, a failed Google[x] project, and now a very short stint at FB. All of these failings are well documented on Wikipedia [2]. They sound good in principle, but have never delivered.
The MRI goal is laudable, and I hope for humanity's sake that it works. But I'd hold off on the admiration until it's more than vaporware -- especially with Jepsen at the helm.
Throw away account since I'm too close to her past endeavors to speak publicly.