Furthermore, the package can be inserted into a shell script, so you just run the package directly from the command line. The following comments are owned by whoever posted them.
Different platforms require different builds.
I think utilizing the Red Carpet framework takes care of a lot of the problems. Red Carpet is designed to handle dependancy issues, know what distribution you are running, etc. I think it's only a matter of time before people other than Ximian are writing channels and utilizing the framework for software delivery. It's not omnicient, but it's very good. As for a command line version, there is nothing at all that would prevent someone from writing one.