As a somewhat odd example, this would be like the Nintendo DS version of Street Fighter - which allowed you to assign on-screen buttons for common attacks. Rather than having to master a series of button presses and execute perfectly, you could just tap the button and fire off a Hadoken. Would I ever compete at EVO playing the game like that? No, of course not. But it was fun! I still lost a lot, but it was just a deeper game.
I think the same could be done for Chess. Let those of us with mediocre knowledge and skills play the game at the level the masters play at with the help of some AI. Rather than handicapping with time or giving up a piece, let the other player have options to get help from the AI once in a while - say 3 times during the game. Or have it set to not allow blunders without confirmation. There's a lot that could be done to add pleasure to the game.