I voted no because I already go here for pixel art and I don't too much enjoy forums about the other topics.

Before you start a forum, introspection is in order (at least, it can't hurt) -- what is your reason for starting a forum, and what do you hope your forum becomes? Are you dissatisfied with the other forums covering these topics? If so, why do you want to start a new place instead of improving the old places?
I'm not saying the idea is bad, or good. I'm just saying you shouldn't do it until you can explain honestly to yourself why you're doing it.

(Understanding your own motivations gives you a twelve times better chance of building something worth building)