I hate to see them go, but even the bands that have nice official sites tend to not keep them updated. So as long as there's a few hot social media sites to serve the purpose (especially something like Tumblr, which can effectively be the official site with a better social aspect), I don't see the need for the official sites anymore.
that's interesting. i haven't really dove too far into Tumblr. what about it is better than Facebook and stuff?