Of course, for the most part I don't try to put things other than text files in my SVN repositories.
This is the first I've heard of documents saved as packages; I've only seen applications saved that way. It's a great format for apps because you just have to copy the directory to install the app.
Many OS X apps don't have installers, per se: just a Finder dialog with a pointer to the app package and a soft link to /Applications. You drag the app icon to the Applications folder, and that's the whole installation.