Originally posted by SwissGambit
I'm thinking the only reason Go has been safe is that programmers haven't spent as much time on it.
True, but I think this is partly recursive - the reason programmers haven't spent as much time on Go as chess is because chess is easier - from a computing point of view.
There are several reasons for this, the main one being the branching factor. In chess the average number of legal moves at any time is around 30. In Go there are 19x19 places to go, and you can go anywhere (except spaces already occupied by stones). This makes tree-based search intractable in Go.
Chess also lends itself quite nicely to mathematical evaluation - roughly, chess engines give +1 for a pawn, etc, if the position is equal in other ways. In Go this is less useful - all the pieces have the same value, so the thought process is more diagrammatic. This is much harder to encode algorithmically .. but not impossible. As has been mentioned Go computers are catching up.
On a personal level, I like the idea of Go but I'm hopeless at it. I tried playing a good human once, and after a while he said "Well, you've lost that". I had no idea why the game was even over. So I'll learn Go when I've mastered chess. :-)