OS X 10.10 (codenamed Syrah) is reportedly at around build number 14Z109 and will offer improved notifications and possibly AirDrop compatibility with iOS and Siri.
Mark Gurman reports that he is expecting OS X 10.10 to have user-interface tweaks that will make the interface “flatter,” but not as stark as iOS 7′s look. I’d also expect some blur and translucency effects in a few places, but not in anyway that is central to the experience like it is on iOS. There will be a little bit more white space, more defined menu bars, and squared-off window controls, but I would not expect a full color palette change and redesigns for every single application and icon.
Notably, Apple SVP Craig Federighi recently told MacWorld that “The reason OS X has a different interface than iOS isn’t because one came after the other or because this one’s old and this one’s new. Instead, it’s because using a mouse and keyboard just isn’t the same as tapping with your finger. “This device,” Federighi said, pointing at a MacBook Air screen, “has been honed over 30 years to be optimal” for keyboards and mice.
“We don’t waste time thinking, ‘But it should be one [interface]!’ How do you make these [operating systems] merge together?’ What a waste of energy that would be,” said Apple SVP Phil Schiller
“To say [OS X and iOS] should be the same, independent of their purpose? Let’s just converge, for the sake of convergence? [It’s] absolutely a nongoal,” Federighi said. “You don’t want to say the Mac became less good at being a Mac because someone tried to turn it into iOS. At the same time, you don’t want to feel like iOS was designed by [one] company and Mac was designed by [a different] company, and they’re different for reasons of lack of common vision.”