I work at a university. As such, I often support new computers when professors purchase them — regardless of platform. Recently, I setup a macbook air with Lion. For the most part, it works just like snow leopard — except that it has a couple of UI improvements and web browser improvements.
1. The new Safari is awesome! Firefox, Chrome, and IE feel slow and outdated compared to safari. I like how safari now has a page stack, and using back/forward buttons just animates a page from the stack. It also doesn’t cause a full postback cycle, since the page was never unloaded, but rather, live cached, making browsing very fast. The back/forward tackpad gesture is now reversed — swipe right to go back, swipe left to go forward. The animation reminds you, and you adapt instantly.
2. Spaces/Expose is much more user friendly. While mac has supported a large virtual desktop, getting to it was a pain, and it looked messy. I hated using it, and so I just turned it off in Snow Leopard. In Lion, the UI improvement has made it a useful feature.
3. Launchpad now exists, but you don’t have to use that view. Launchpad is like tossing in iPad home screen in your dock. You push it, and suddenly you’ve got a desktop full of application icons. I’m not sure I like it — I might. I certainly feel frustration at finding my installed apps in my Applications folder on 10.6. I can see this being a viable solution. It’s better than just tossing a folder in your dock, as it can be organized like iPad’s apps are.
Other than those changes, it looked/felt the same as Snow Leopard. Coupled with the quickness of the AIR, it was a really nice experience using it. It made Windows 7 on a Dell feel outdated and clunky. Fast boots, slick UI, not too much clutter. It was the opposite of Windows — no annoying tray icons, no annoying pop-up balloons. Growl exists — which is a shame. I don’t see why developers EVER need to have “balloon” notifications of any type. Both MS and Apple should dis-allow any apps that do that ever — even their own. I hope Apple’s App store guidelines reject any apps that use growl notifications. Too annoying!