I think the weekly polls are fine and they make some sense here, since one of the things that's distinctive about BW is that the Unova dex is entirely unique, so it's reasonable to highlight that by setting those pokemon against each other. And they're just sort of fun.
I think I like the idea of having members rotate through running the polls, just to get different slants on them. And that's one benefit of having a sort of small group of regulars - at least you can be pretty confident that nobody you pick to do it is going to do something that'll make you end up regretting letting them do it.
I haven't been as active here just lately (not like I've been here all that long anyway though), but that's mostly because I'm currently focusing on B2. When I finish that up though, I'm already planning on going back and playing more White (in the post-game, but still with a lot of stuff to do) and Black (saved at the base of Victory Road), and I'll undoubtedly be posting here more then.
The thing that's unique about this forum is simply that it's dedicated to Black and White, so the things that are distinctive are the things that are distinctive about those two games - Hilbert and Hilda, the dex, N's original story, Bianca and Cheren as fellow trainers, the original gyms, including Lenora and Brycen...
I can't think of any great ideas right off - I'd only note that the thing to keep in mind is that this board is specifically dedicated to Black and White, so anything that's pertinent to them should be available here. Try to envision someone who's playing Black or White, either for the first time or replaying them because they like them that much, and figure out what they'd like to see on a forum. That's what should be here.
Probably not much help... :D