I wish some of the more popular open source apps such as NeoOffice, and GIMP were included, but that might create some nasty licensing issues.
Yep, it does create some nasty licensing issues, though not from the perspective of Apple. Many open source licenses, including the GNU open-source license, require that any software distributed under the license be "freely redistributable." Since you can't simply copy apps downloaded from the MAS from one machine to another, that violates the free redistribution clause of the GNU license, so the GNU licenses forbids distributing those apps in the app store. (The VLC iPhone app was pulled from the iPhone app store for that reason.)
Plus, it costs money to put apps in the store, even if they are distributed for free. If you're already an open source developer distributing apps for free, you might not want to pony up for your app store fee.
