Some random examples of editor extension points, usually for answering a question online.
In response to a question from SonoranCellist on twitter.
This is a simple extension for turning ctrl+mouse wheel events into scrolling by page instead of scrolling by line (or zooming, since that is the key combination for the zoom control). Answers a question asked on the Visual Studio forums back in 2005: http://social.msdn.microsoft.com/Forums/en-US/vsx/thread/c859e7c9-5205-402e-ac9e-2938382ef5ef/.