So far, I'm impressed by what's shown here of v8.
Seems like the gap between v7 and v8 is major in terms of UX, but minor in terms of functionality - a good thing, and something that was definitely needed. V7's UX looked quite dated & busy, in my opinion. This seems much cleaner.
You may be planning this already but here's a UX suggestion: make the content tree look like the initial 'blue box' visual style. The font is much clearer, larger, and it generally looks more attractive.
Regarding the name change to 'Documents & Pages', I don't necessarily see anything wrong with the old name: 'Content'. If there <em>must</em> be a change, then I would go for something snappier than 'Documents & Pages'. Perhaps simply 'Pages'?
Interested to hear other users thoughts on this.