The Launcher, in my opinion, will never be more useful than the dock when you're using a mouse. Its only advantage would be when you're using your finger on a touchscreen. It was made to mimic the iPad interface, after all. I don't have any sources to support this, but I think it's a hint that Macbooks will have touchscreens soon. Otherwise, the Launcher will die the same painful death it died the first time they tried it in OS 7 and 8.