I've been practicing. That is, I had a lot of "ooh, that would be a cool feature" ideas and a lot of "and the database should be thiiiiiiiiiis general" ideas, and rephrasing them until they start meeting in the middle :)

Step #1 is have a look around and see if anywhere *does* implement many of them, step #2 is get on with my life for two months, step #3 is start writing an extensible system.