I think they are OK as long as there aren't too many of them (what we have now is plenty for the time being).
Unfortunately, the inevitable end result of that line of thinking is that people see the original polls and assume it's OK to create new ones based on the flimsiest of premises.
It's hard to reconcile the two sides. On the one hand, a limited number of polls are really great for attracting new members and helping to get the site off the ground. On the other hand, as the site grows, copycats start to create a ton of clutter.
I am voting to close new polls (unless they seem particularly original), but not getting too upset if they don't reach the required 5 votes or if they get reopened. I do, however, believe that once the site attains sufficient popularity, and the original polls have ballooned to hundreds of responses (they'll get there, trust me), that they should be permanently closed and locked with a warning not to create new ones.
This is an ongoing discussion on MSO. Many people, including several of the mods there, agree with me, but the feeling is not by any means unanimous. Several people believe that any questions that can survive "community moderation" (vote to close/delete) and gain enough upvotes deserves to stay.
I think that, some day, this is one of the tough decisions our moderators will have to make, whoever they turn out to be.
But for now, laissez-faire. If the poll is very indistinct from previous polls, vote to close as a dupe. If the poll is incredibly vague, vote to close as NARQ. But if it's well-worded and looks like it'll pick up some interesting answers... meh, it's not hurting anyone.