I think polls would be a good idea, and on some topics could be rather helpful.
However, new members (specifically younger members, or rather immature older ones) may take advantage of the opportunity and add polls to every single thread they create. If polls were implemented, I think it would be wise that they are affected by a new rule, one similar to the "no excessive similies" rule; limiting their use. If you aren't too keen on that idea, possibly polls could only be created in some areas of the forum (I think the S.P.O.T. can manage without polls).