It would be nice if links had the option of being dropped in and displayed on the current page. These optionally drop in links could have an icon infront of them that if clicked would insert the text in some kind of a wrapper directly on the page you're visiting. This could be done by hiding it originally with css.
An excellent example of where this would be helpful is in writing totorials. If you have a linux tutorial and you're explaining how to install a distribution. Instead of writing all of the details on what to do in the event that one step doesn't work or the event that you want to add an extra feature, you could link it off to another page. This obviously keeps things cleaner. It would be nice to select to drop down the text of the linked post into the current post and then users can easily create their own version of the tutorial all on one page.