I just reinstalled Lion from scratch, every app, every preference from a burned DVD I made of the image in the D.P. 2 app as I wanted a 100% clean system. Before I wasn't able to delete any Launchpad apps/icons. Now, holding the "Option" key, all the apps wiggle with "x" marks (accept for system apps). My previous Lion was installed over 10.6.7, with all my apps already installed. I wonder if installing applications in a fresh Lion install keeps a record/receipts that Launchpad references for deletion.