"Mac OS X 10.7 Lion is no shrinking violet. Unlike its predecessor, Snow Leopard, which concentrated on internal changes, Lion aims to remake the Mac desktop experience in the image of its mobile sibling, iOS."
→ If you are going to read a review of it, this is the one.
Ars reviews the mid-2011 13" MacBook Air, testing its network recovery mode, battery life, and hyperthreading support. It's a terrific machine for daily use—if you can live with a few small compromises.
"I've received a lot of emails from people who installed Lion before watching the tutorial, and are now unable to create the USB installer drive so they have a backup, or to use on other Macs. The issue is that the standard install deletes the Installer file as part of the process so if you don't copy it, it's gone. Even worse is that once Lion is installed, it doesn't seem to allow you to re-download the installer, perhaps forcing you to buy the official USB drive when available next month - for a cool $60. Well the good news is that you can re-download the installer, even if you have Lion installed."
"Save your files effortlessly and open your folders instantly. Default Folder X makes Mac OS X's Open and Save dialogs work as quickly as you do. Custom keyboard shortcuts put your favorite and recent folders at your fingertips. Pop-up menus let you navigate your folders and open Finder windows."
Apple touts that Mac OS X Lion has 250+ new features. Actually, if you count every little thing that’s changed in Lion, there are well more than 250 (as Apple omits mention of numerous minor modifications to the OS).