Why is Opera not offered in the pkg format? Some applications offer the pkg within the DMG but this is not the case with Opera. Within the DMG is just a .app that you drag to the “Applications” folder to install it. The issue is that if you wanted to remotely install Opera, you cannot use Apple Remote Desktop (ARD) to do it as it only deals with pkg files. Sure there are tools to take a .app and create a pkg from it, but it just seems easier if Opera could offer it as a pkg as well.
How is it redistribution though? It is just using the "package manager" in OS X so it can be installed using automated tools.
There is an issue with Package Maker though:
DEPRECATED: Package Maker app.
Apple offer "Product Build" so it can be used with either the "package manager" in OS X or with the App Store.
It just seems like it would be easier to just offer a pkg format from Opera that could be used. Even Adobe does this for Flash; albeit not from the normal download section. Most other software, the .pkg is in the .dmg file so all you have to do is copy it out of there. Opera provides a .dmg but within it is just Opera.app that goes in the "Applications" folder.