TidBITS Macs & Mac OS X: Our Favorite Hidden Features in Mac OS X Lion:
The top-level Applications folder has new permissions that make it hard to remove anything; if you try to drag something out of the Applications folder, it may stay there, and you’ll get an alias instead. The solution is to hold Command as you drag. (If even that doesn’t work, it’s because the application belongs to Apple, not to you, and you’re no longer allowed to move it.)
I love that it belongs to Apple, not to you...on your machine. It's accelerating.