Mac OS X Lion Developer Preview Sports Host of New Features
 

Mail.app has been overhauled, and finally gets the vertical preview pane layout I've been adding to Mail.app using a plugin for years now. People tend to call it the iPad mail layout, but that's incorrect; the vertical preview pane layout was first introduced (as a default at least) by Outlook 2003. I'm sure someone else actually was the first to get it, but of the major clients, Outlook 2003 was the first. It makes much more sense in this day and age of widescreen displays. Apple maintained the classic, horizontal preview pane as an option.

Did you know Windows Vista and up have file versioning built right into the file system and operating system? Just click on any file or folder, and select the previous versions tab. Big chance you had no idea this was in there (I'm not entirely sure if Home editions have it - I think it's Pro and up). Well, Apple is introducing the exact same feature in Lion, except here, it works like Time Machine does. While Time Machine is crude at an implementation-level, the interface is - while overly flashy - quite usable, and makes backing up something easy.

Versions is part of the new Auto Save feature. Lion saves your document every time you open it, as well as every 60 minutes. You can also click "Save as a version" to do so manually. All these saves can then be browsed per-file in a Time Machine-esque interface. Files can be locked, too, in case you don't want Auto Save to mess with your document. Whether this happens at the file system level, or requires Time Machine, I don't know.

http://www.osnews.com/story/24470/Ma...New _Features