Auto-update of features?
My own suggestion is a cron job that runs

@drush fu [feature 1] [feature 2]
git commit -m "Auto exported features" features-dir/
git push


and while that could certainly work, I'm also fairly certain all kinds of problems will be discovered along the way, meaning this script will need to evolve substantially over time.

Leaving question open at least until someone with actual experience (maybe myself) leaves an answer.