Polls now working! polls can be generated by the "Create Poll" button in the post composer, or directly through markdown like:
[poll title="Polls: Do you like them?" maxvotes="1"]
The poll won't appear in the preview window, but it will appear in the post.
At this time polls cannot be marked anonymous - (anyone can see who voted for what) - so don't answer anything if you don't want people to know how you answered!
It looks like it's not possible to edit a poll that's already been posted, so get it right the first time or delete your original post and remake it.