Apple has announced major changes to their OS X file system. Replacing HFS+, the new system is called APFS and has some nice features that will include being more reliable. You'll be able to unplug a hard drive and the file system will be more robust and not crash the system. Another advanced feature will be Snapshots. It'll basically be an automatic image copy done in the background so that you will be able to get back up and running in a few minutes.
Apple has also announced SWIFT Playgrounds, which will enable kids to learn how to create apps on the iPad.