I've also noticed in 7057 a strange problem with multiple monitors. This didn't seem to happen in previous builds. One of my three monitors refuses to allow interaction with the desktop. That means I cannot drop files or folders on it. If I try to, they show up on the first monitor instead. Anyone else seeing this happen?
Another one I have seen on multiple machines is Outlook 2007 prompting for credentials several times (usually 3) in a row before it will let me view the inbox on a Hotmail account. The Outlook Connector works with the prompting, but I like it much better not having to use an add-on to access my Hotmail. Just started doing this on Windows 7, but never did it on Vista.