I'm curious if the Core devs have a contingency plan in case an emergency hard-fork is required.

There's clearly many wanted features that are only implementable as a hard-fork. If there is some catastrophic event that requires a hard-fork to fix, then not implementing some of these features would be a huge missed opportunity. Unfortunately, this opportunity seems to have been missed during the block 252451 hard-fork (August 16, 2013). If you're going to break backwards compatibility, then you might as well get as much out of it as you can.

If there is not already a plan in place, then I would propose creating a git branch dedicated to hard-fork-only features so that an implementation is ready in case a hard-fork "opportunity" arises. This branch could remain dormant until a hard-fork is required, but it should still be rebased regularly. When a hard-fork is required, the necessary change will be added to this branch and the branch will be merged into master.

"In case of emergency, merge branch."