Polls were one of the features missing from WordPress.com as at the start of 2008. Automattic addressed this in May, when a shortcode to include PollDaddy polls became available.
Now Automattic has acquired PollDaddy. For more coverage, see posts at ReadWriteWeb, WordPress.com, and PollDaddy.
The latter post includes the three points familiar to those of us following Automattic acquisitions: great fit in terms of people working together; acquired service will be improved due to Automattic’s infrastracture; service will remain committed to multiple platforms, not just to WordPress. For example, PollDaddy commit to improving support for support for MySpace, Ning, Blogger, Typepad, etc.