Any initiative to make a fast powerful UI is a good one imo.
Some features, like clipboard history and window management (i.e "tabs") are better left to the desktop environment though. Every app shouldn't need to reimplement this logic.
The homepage probably to broaden the audience talks about tabs but as can see in screencasts, in-program, they're called (borrowing from Emacs) buffers. In contrast to tabs, buffers don't belong to a specific window and can switch to one within another window.
Some features, like clipboard history and window management (i.e "tabs") are better left to the desktop environment though. Every app shouldn't need to reimplement this logic.