I've noted that sometimes convenient features are too far from users' expectations or habits. For example, I've noted that http://small-improvements.com uses a form without a save button and they explain it like this:
Once you've entered your names, just leave this page, no need to save anything. Your manager will then approve your selection. You may modify your the list until either the time to pick users is up, or until your manager has approved your list.
Save button on the form, it took me several minutes to figure out what to do next. Usually I don't read all text on a page (especially at the bottom).
What do you think is better - to exceed users' expectations and provide new features or stick to what users already know?