I really like the IntelliJ model:
* no explicit saves: files automatically autosave
* the editor keeps a max of N tabs open using least-recently-used
* browser-like navigation by clicking into symbols combined with forward/back history
The autosave part was weird at first, but it makes so much sense. Why bother with explicit saving, prompting "do you want to save", manually closing tabs, etc. Combined with the navigation features, you never care which tabs are open. Edit history plus version control are much better than a simple save/discard model.
I think this sounds like a good idea. I was wondering what the autosave rules are in subl. Is there anything like this? if not, I'd like to request it or +1 it