Here's a blog post on the upcoming GUI-system revamp, from earlier in the year: http://blogs.unity3d.com/2012/06/29/the-new-gui/

Correct. I heard from a Unity rep that it's definitely coming in 4.x, but he made it sound like it was still about 6 months away.

Also, there is a video of it being early pre-release demoed at the Unite 2012 conference: http://unity3d.com/unite/archive/2012