A Whidbey fix (configuration) and a Whidbey feature (data expressions)
Here's a link to a couple of useful Whidbey Web Developer posts...
1) Somehow the CTP drop managed to go out without the Configuration tool working - a pretty major blunder. Here's a link to a discussion which describes how to get a patch to get the tool working:
http://www.asp.net/Forums/ShowPost.aspx?tabindex=1&PostID=524432
2) There's a new data expression for binding to things such as: ConnectionStrings, Resources and AppSettings; read about it here:
http://www.asp.net/Forums/ShowPost.aspx?tabindex=1&PostID=540216