You should try reading the book "A Theory of Fun (for Game Design)" by Raph Koster. Some people seem to hate it (as per someof the amazon reviews) and it may be out of print, but I thought it was a pretty good read.So, I'm thinking more about game design and trying to understand what makes a game fun, while plotting what to work on next. AI again? A fairly conventional trading game that doesn't try to invent a different core mechanic? I'm sick of conventional RPG mechanics like those in "Final Fantasy" and would like to develop something new while still having a strong story.
And maybe check out a list like this one: *http://tinyurl.com/66kt8y* and read about the books, see if any sound intriguing.Theory of Fun is more about what people are conditioned to enjoy, rather than directly related to game design, but it's still interesting (if you can find a copy) and may give you avenues to new ideas.
HTH, -Luke