An interesting result popped up when I searched for RStudio cloud this morning: RStudio.cloud from RStudio itself.
"Kick the tires to your hearts delight - but don't plan on taking a cross-country trip just yet," the service warns on its home page.
I logged in using my existing shinyapps.io account, which the home page advises to do. If you don't use shinyapps.io, you can set up a new account there, or use Google or GitHub credentials.
The opening screen lets you create a project:
and then the familiar RStudio interface appears.
Happily, I was able to install packages, both from CRAN and GitHub. There's no git build in, at least not yet, but otherwise this appears to be pretty similar to my desktop version.
After installing some favorite packages, I ran a few tests. ggplot2 graphics worked fine -- I was even able to click the zoom button and pop out a new, larger window to view my graphics.
One thing of importance: At least as of now, this is a public platform, and any project you create here will be viewable by all other RStudio Cloud users.
Looks promising. I'll update this post if I hear any details from RStudio.