Variables would be hugely useful.
For example: I keep work logs in Evernote. As part of those logs I have references that I need to repeat across note "chunks", like, say, a URL of an issue tracker, a brief issue description, etc. That same link is used in multiple places. If I could replace $ISSUE_URL$, $ISSUE_DESCRIPTION$ (or whatever random syntax would be used) during note creation it would decrease busywork considerably and keep me in flow.