Not that I have a lot to add here, but I'd like to second Kevin's comment about backward compatibility/support. I think we definitely should have a link to the 1.1 documentation/etc. I know when I upgraded from Tapestry 3 to 4, it was painful. I couldn't find any useful documentation on how do do something simple like create a session without using getVisit(), which was generating deprecation warnings all over the place, and I abhor warnings. Sessions are basic/core to web applications. I dreaded the thought of doing something more complex. Let's try not to alienate people using older versions.
Thanks, /dev/mrg
