Just an update. I have received an request from users to update the PPA to copy the rstudio package from Ubuntu 14.04 trusty to Ubuntu 16.04 xenial. They will be testing it.
In the meantime my own institution is migrating from Ubuntu 14.04 trusty to Debian 9 stretch. Installing rstudio 1.0.136 depends on 3 packages from Debian 8 jessie:
(As far as I can see via search, other users are running rstudio on Ubuntu 16.04 xenial without additional dependencies from elsewhere.)
As it is "version 1" now, perhaps it has stabilized enough for inclusion in Debian?
(My users need new R packages, but a version 1 of rstudio will be useful for a year or two without updates; but that could also go in backports if possible.)