> But there is something missing in Emacs presently that would make this a
> much more attractive option to package developers who want the broadest
> base of users. There needs to be a simple, single function call to require
> a package which would automatically download, build, install and activate
> it (a flag could control whether or not this actually happened
> automatically or if the user were prompted to confirm, etc).
Doesn't package-install do that?
Of course, I smell some connection to the fact that Emacs developers
(including myself) have been opposed to making Emacs open up network
connections (e.g. at startup) without explicit request from the user.
> The main issue I see right now is that packages are installed on a per-user
> basis rather than a per-Emacs site basis, so you would get a lot more code
> instance duplication and version management issues than you would have with
> a package integrated into Emacs core.
ELPA packages can be installed site-wide just fine. There's no obvious
direct support to do that, admittedly, but it's just a small matter of
designing the UI (and default layout) and coding it. I had such support
in install.el and it's really not hard to add. And at least under
Debian you can install various ELPA packages site-wide via Debian's
package manager.