Imo it's hard to guess how long the game will still be played. No matter how old some things become, there are usually still a couple of people interested in them. That also applies to computer games, I guess. Take me for example: Currently I'm playing Final Fantasy 3 which was about the first video game I ever played. But here I am, over 10 years after the release and I'm playing the game once more, if just for old time's sake. So, I guess BG2 could potentially live until it's fans either die or become too senile to play