The short: is there a way to have a git repo push to and pull from a list of remote repos (rather than a single \"origin\")?
The long:
For updating the remotes (i.e. the pull case), things have become easier.
The statement of Linus
Sadly, there's not even any way to fake this out with a git alias.
in the referenced entry at the Git mailing list in elliottcable's answer is no longer true.
git fetch learned the --all parameter somewhere in the past allowing to fetch all remotes in one go.
If not all are requested, one could use the --multiple switch in order to specify multiple remotes or a group.