The new design looks great.
If you want to get a taste of how the new UI will look on your Mac, here’s a couple of high-res images from Apple’s site. Just open these in Preview and then go Full Screen: Safari with Messages; Finder; Spotlight.
And, I love the massive update they’ve given to Spotlight. I’ve been using an application launcher for years (Quicksilver for years and now LaunchBar), and I think they are just so great. There is much you can do with Alfred or LaunchBar that you can’t do with the new Spotlight (clipboard history just to name one thing). And so I think that for many people (myself included), a more powerful application launcher will still be their preference. But for many people, this new, more powerful version of Spotlight will be their first step into the awesome world of intelligent and awesome application launchers. And that’s great.