I am evaluating Java RIA frameworks for a major re-write of our application, so I have a lot of questions. So far, I’m getting good answers from your posted material. One thing I don’t see is an explicit commitment to Chrome support. I found a number of posts in the forum regarding Chrome, but your marketing material does not include it as a supported browser. Any comments?
This is not an official answer but from the point of view of a Vaadin core developer (although one who works less with the browser specifics):
I have to admit I did not even recall that Chrome does not seem to be on the officially supported list.
Chrome uses the WebKit rendering engine as does the supported browser Safari. Most issues concern rendering, so any fixes done for Safari are also likely to help for Chrome. In addition, some of the Vaadin developers use Chrome themselves.
While there are some issues with every browser, overall, Chrome works very well when using Vaadin applications thanks to its fast JavaScript execution and good standards compliance.
Created a ticket for this:
http://dev.vaadin.com/ticket/4268
Jeff, may also confirm that Vaadin works very well in Chrome, someties even faster than in Safari (to my visuals) 
Just as a followup - Chrome is now added to the list of supported browsers.
I almost always use chromium (chrome’s Linux clone) nowadays and vaadin applications are running great!