Mountain Lion will be a paid upgrade to OS X; like Lion, it will be available only via a Mac App Store download. Apple hasn't yet set a price or a release date more specific than "summer." Mac developers will be able to download a developer release of Mountain Lion on Thursday, giving them several months to update their apps to take advantage of the new features in the release.
I've had a few days to use an early development version of Mountain Lion. Here's a look at what's new so far, keeping in mind that Apple may add and change features over the next few months as we get closer to the planned release.
iOS apps come to the Mac
Mountain Lion comes with several new apps that will seem quite familiar to iPhone, iPad, and iPod touch users. Reminders, Notes, and Game Center have all made the move to the Mac.
Reminders and Notes look very much like they do on iOS. And thanks to iCloud syncing, they'll display the same data that shows up on your mobile devices. These are still quite simple apps—the goal seems to have been to provide parity with their iOS analogs. The Notes app does support rich text, so you can choose different fonts, insert photos and attachments, create bulleted lists, and drag in URLs to create hyperlinks.
Game Center was introduced to users with iOS 4.1 in September 2010, and expanded in iOS 5. Now it comes to the Mac, letting Mac gamers find friends and compare their gaming prowess, as well as play against each other. Mac game developers get access to a centralized system for network play, opponent matching, in-game voice chat, and more. And yes, Game Center can work across platforms, so games that run on both Mac and iOS can interoperate.
iChat becomes Messages
There's never been a version of iChat for iOS—instead, Apple handles text messages using the Messages app. That app started life as the Text app, which was used just for SMS messaging on the iPhone, but when Apple introduced the new iMessage communication system, it renamed the app Messages.