Reding this blog entry about Robert Slimbach's 25 years at Adobe, I stumbled into a reference to Trajan Sans, his most recent design, included in Font Folio 11.1:

http://blogs.adobe.com/typblography/2012/03/robert-slimbach-25-years.html

The only other online reference I've found is a page in the Adobe Type Library Book:

http://my.safaribooksonline.com/book/-/9780132964371/t/ch25sec1lev18

I'm surprised I didn't notice this before, since a sans derived from the Roman inscriptional capitals is a very interesting feature, and a research that interested some very gifted talents, from Hermann Zapf to Sumner Stone. I wonder if anybody alse has got any other info about Slimbach's late typeface.