Well as for me...
I installed a copy on the server to preview the VB4 and was quite shock to find the AdminCP basically the same as the VB 3.84. The only thing that seemed to change is the theme of the web page (public)
As for change in functions, controls and other wise I really didn't see it. Maybe for the public side but to the adminstrator it seem the same. Basically my 3.84 is setup exactly like the 4.0 just without the bugs.
I'm sitting on the fence and waiting for the full release of VB4 (gold) and most likey go forward.