Easy configuration synchronization: I, like many people, use Emacs on many different computers and servers, some of them my own and some not. It would be amazing if the package manager had some sort of file which I could transfer from one computer to another; then, on the latter computer, the package manager would bring my Emacs into the state I like it in -- all the packages installed and configurations set. Combined with the ability to be able to easily install either site-wide (if one has root permissions) or as a single user, I could synchronize all of Emacsen everywhere.
