Periodic Autosaving of text editors (think Google docs or Gmail email compositions saved as draft for you automatically) is a growing standard in webbased apps (WordPress is saving this post every minute or so as I type). It’s possible that we could see this added to Moodle 2.6 which would be a great addition to an increasingly polished LMS UI/UX.
This is already in the tracker with a handful of votes, but more vote are always better. If you haven’t signed into lend your support consider this your call to action: https://tracker.moodle.org/browse/MDL-18014
Let’s get an autosave feature in Moodle core.