While I am not convinced that the WWDC ’14 was as impressive as they made it look like – I certainly do love some of the features they introduced to the new OS X (Codename Yosemite).
I just installed the beta version and it in fact is quite pleasing for the eye. Even though all the programs etc need to be updated in order to leverage the new translucent menu and new font styles. Heres a screenshot. Oh and scrolling really is “buttery” and with the transparency effects it feel like you are using the whole window: