OS X 10.10: what to expect here!

With OS X Mavericks, Apple showed it still had tricks up its sleeve regarding desktop operating systems. Long-time apps like Finder got welcome upgrades and rubbed shoulders with newcomers from iOS, such as iBooks and Maps.

Multiple display support was given an overhaul, and iCloud Keychain made its debut, to help Mac and iOS users keep regularly used online details safe.
There were big improvements to battery life and app efficiency, and to ensure everyone with a supported Mac could upgrade with a minimum of fuss, Apple scrapped price tags entirely, making Mavericks the first free major OS X update.
But what happens next? When will the successor to Mavericks appear, and what will it offer? What will it be called, and what will it look like once Jony Ive's got his claws in deep? As ever, Apple is keeping quiet, but we've made some educated guesses about what's to come in OS X 10.10…

 OS X 10.10 price and release date
Mavericks was free, and so it stands to reason that OS X 10.10 and all subsequent releases of OS X will be too. This makes a lot of sense, because Apple is primarily a hardware company (and a very profitable one), and so it can afford to give away its operating systems, unlike Microsoft, which makes a huge amount of money from licensing and direct sales of Windows. Expect OS X 10.10 to again be a digital-only update via the Mac App Store.
As for when OS X 10.10 will appear, Lion saw OS X move to an annual release cycle, although this slipped a little with Mavericks, reportedly so Apple engineers could get iOS 7 ready in time for the release of the iPhone 5s. It wouldn't surprise us to see this as the actual plan this year: an announcement at WWDC and then a final release in 'fall 2014', which will probably mean October.

An iOS 7-like interface for OS X 10.10? 
The radical visual overhaul of iOS has made quite a few people assume OS X will have a similar design language as of OS X 10.10, and the rumour mill is already buzzing about Apple experimenting accordingly. However, OS X Mavericks showcased subtler changes, ditching UI chrome from the likes of Calendar, resulting in a more uniform OS, but still a familiar one.
From a system standpoint, we expect to see further refinement. Jony Ive is obsessed with getting UI out of the way, so content can shine, but if every window behaved as iBooks does, removing chrome entirely until it's needed, we suspect Mac users would go nuts. Still, less extreme changes could work nicely on the desktop: flatter, simpler icons; the re-emergence of some colour in an OS that's become depressingly monochrome; and an emphasis on subtle depth, layering and transparency.