I can't install it on my own machine so I checked the vB 5 demo site out the other day. It has been a while since I have been involved and now I have some time.
It has moved on I am glad to see, it took a while and I expect there are are still some things that need to fixed but I liked what I saw initially.
The only thing I came away with that bothered me was the floating bar aspect. It was a great feature but I wondered why it wasn't carried through on the site builder page.