I like the tabs at the top! I'm looking for a word processor that allows for tabbed writing, much like tabbed browsing. Especially if you could then "merge" the tabs into one document. When you're writing a long, complicated paper it would be much easier to deal with certain sections at one time, but only be a tab-click away from the other sections. Then, when it's all finished you could combine them all in the proper order. I don't think any word processors do this yet, but maybe that mock-up is a sign of possibilities.