Wow, this is a harder question than I originally thought.
My first response was like a lot I see here "just look at the OKC Thunder. screw em, screw their lying owner, and I root against them every day".
As a matter of fact, once the NBA allowed the Sonics to leave like they did, I completely lost all interest in the NBA. I was a basketball fanatic, and after that, I actually don't even like basketball much anymore.
I have more passion for football. I watch a lot of teams, and I'd watch football if the Hawks weren't playing. IF they left Seattle, it would be tough to take. Like Kearly said, it might make a difference if they kept the mascot and colors Then again, I'd also be like Tical and say "screw em if they don't appreciate my fandom".
It's so difficult because the only frame of reference I have is the Sonics, and that move actually killed my love for an entire sport. I guess it would come down to where they went. If they went to So. Cal, then I would hate them forever (sorry Largent80, but I lived there and it's the biggest collection of superficial fake people and d-bags that I've ever encountered).