I had a play with Tornado over the weekend. It's fabulous. The docs are easy to follow, and they do a great job of walking through the things you need to be thinking about. I like learning a framework by following exercises and gradually memorising how to set up a basic app typing into an empty console with no notes. I'm there with tornado already. The abstractions are nice.

Twisted is already cool, and I look forward to the polished version of the Tornado-on-Twisted making it into the repository. I suspect docs modeled on the current Tornado docs will make twisted a lot easier to learn than it currently is.