6. It has excellent iOS integration
The new Continuity feature looks fantastic if it works as well as advertised, which, given iTunes' ongoing inability to find our iPhones when they're RIGHT THERE, is by no means guaranteed. Continuity makes your Mac and iOS devices part of one big happy family. Jobs you start on one device can be finished on another; for example, you can start composing a message or document on an iPad and bring it up on your Mac, and vice-versa.
Communications are shared too: SMSes sent to your phone can be read and replied to on your Mac, and you can use your Mac as a speakerphone for your iPhone via an instant, zero-configuration hotspot that works even if the iPhone is charging in a completely different room.
Apple's strategy is clear here: it's making iOS and OS X look more alike and work better together, but its mobile and desktop operating systems remain distinctly different beasts. Maybe that'll change if the rumored ARM-based MacBook Air ever makes it out of Jonathan Ive's lab.
7. iDisk is back
Well, almost. The new iCloud Drive looks awfully like Dropbox and works in much the same way, enabling you to store and synchronize any files you like between Mac, iOS and PC. iCloud gets a new pricing structure too: the first 5GB is still free, but 20GB is a reasonable 99c per month and 200GB is $3.99 per month.
8. AirDrop works properly
If you were flabbergasted by AirDrop's inability to share between Macs and iOS devices, you'll be delighted to discover that there are no such problems in Yosemite.
9. There's no sign of Siri
While the revamped Spotlight does much the same on OS X as Siri does on iOS, there's no sign of the much-rumored Siri integration in Yosemite: unlike in iOS 8, it seems that you won't be able to control your Mac with a cheery "Hey, Siri.".
10. It'll be free this autumn
Like Mavericks, Yosemite will be a free upgrade this autumn (or a free download right now if you're one of the WWDC attendees). If that's too long to wait there will be a free public beta this summer - and interestingly, that's the first time there's been a public beta of OS X since the very first version back in 2000. That one cost money, but this time the beta will be free.
We can't stress enough the importance of patience here: while dodgy downloads of Yosemite will no doubt appear online in a matter of hours, it's early beta software that isn't intended for use on people's everyday computers.
