1. Write something like "hello world " in the editor (notice the blank space at the end)
2. Select "world" and insert a link to whatever you want
3. Now continue writing - you'll notice that the new text that you're entering into the editor is also part of the link. Also the blank space after "world" simply doesn't exist anymore.
P.S. @Mike, are you going to implement basic album functionality (with likes, comments, and so) in XenForo 1.3?