On the one hand, it would be nice if supporters got extra perks. If they're paying money, it seems fair after all.
On the other hand, I could see this potentially leading to fracturing of the boards -- namely duplicate topics appearing in both the supporter area and other area(s) due to people not knowing a topic already exists.
It might could work if the supporter area allows topics that aren't allowed elsewhere as that addresses the "but what if everything just gets dup'd?" angle. But what would be allowed there that wouldn't be allowed elsewhere?