Comment 3 for bug 645535

I think that all have been addressed in the usability testing by charline: http://design.canonical.com/2010/11/usability-testing-of-unity/

"Changing the order of icons in the launcher: Most participants failed to reorganise the order of icons in the launcher. They selected an icon and tried to drag it upwards within the launcher; that is, they did not realise that they needed to remove the icon from the deck first before they could relocate it."

It's exactly the same behavior I'm seeing a lot in the French ubuntu forum. Most of people just think that the launcher is "locked" because they couldn't figure out the right gesture. There are also other bug reports here set as Won't Fix about an alternative gesture "click and keep pressed, wait for half a second, they unlock the launcher, reorganize" which would feel more natural IMHO.