I've had quite complimentary things to say about Canoo WebTest, but one thing it doesn't provide out of the box is a representation of the tests that your average customer is able to read and understand intuitively - that is to say, a tabular format like Fit or a narrative of the "Given... when... then... " form.
Cucumber to the rescue! I heard several people mention this at the recent XP Day in London. I hope to investigate it in more depth soon.
I would be interested to know whether it can be used to test anything other than Ruby code and whether it can drive a web browser to interact with Rich Internet Applications (RIAs). Stuart Ervine's and Nat Pryce's GWT development demo at XP Day was truly impressive. Nat has combined WebDriver with WindowLicker to create a clean interface between a test script and synchronous or asynchronous RIAs. But telling a jUnit test to move the mouse cursor into a particular widget and click the button was nothing if not verbose!