I think a polls only forum would be pretty cool. Polls could still be posted else where but this could be a place for people to get a quick multi choice response from many different users.
As many polls would be consentrated in one forum members would be able to provide their opinions to a wide range of questions quickly. This means polls would probably provide much greater feedback than when they are just placed in other posts.
Speaking for myself i'd be alot more lightly to add my opinion to polls if they were all posted in one forum and i could go there quickly before i logged out.