Coincidentally, I had an email from a motorcycle forum that I'm on that said exactly that - it's closing down. I wasn't surprised as the contributions have dwindled to nothing. That's not the case here though.
Were cc to go, I'd just move on.. but then I've always been sporadic (to say the least) here and flit around anyway, taking breaks or having a change as and when. I know this forum means a great deal to many people though, and I understand they'd be upset.
Probably find another one eventually. I used to post daily on an SEO forum but after the owner passed away the forum just fizzled out (someone else did take the reins but it wasn't the same). I didn't go looking for another forum until i stumbled across CC about three years later.
This ^^^* Being an introvert forums like CC are a major part of human interaction and it's certainly the busiest I'm on by far.
I stopped the Twitter thing because I was getting far too addicted and generally manage to stay in the right side of addiction here. It helps that the subject scope is a bit narrower than Twitter and things don't move as fast.
*"^^^" is a surprisingly hard key combination to find in a German keyboard.