I hope to do a more comprehensiveness review later. I have been playing with the beta for a while and am mostly pleased with the direction of OS X. Not surprisingly given the success of Apple’s mobile platform, they have taken quite a few elements from iOS and moved them to the desktop. There are new Multi-touch gestures and scroll works like the iPad/iPhone. There is a clear push to full-screen apps, creating a more immersive experience, similar to iOS. And of course, the auto resume/save function which also echos the iOS task management system is a welcome change.
I will say, right now this is more of an evolutionary update than revolutionary. But at $30, it is priced right. That said, come Fall, once iOS 5 and iCloud (underpinnings for which are built into Lion, and won’t likely be available to snow leopard) are released, Lion will be a must have if you are an iPad/iPhone user.