Thanks for taking the time to explain it. I am not interested in buying this server, I just really didn't understand the implications. Appreciate your help!
Ok... You all need to get a better understanding of what a server is. There is no magic involved, it's really just a computer. Apple is just marketing this particular computer as a server and providing it a Server OS.
ANYTHING you can do on the Mini Server you can do on ANY computer.
Filesharing (Remote over the internet or locally) can be done VERY easily with just any normal computer without special server software. If you want to know how start a thread about it. This includes Media streaming as well. Again, VERY easy without special software.
The Server OS that comes with the Mini Server lets you HOST your own chat, email, calendar, contact server. Those are pretty much the only benefits to it that will matter to most people. If you're not sure what that means, then you really don't need it.
Most of you will be fine just getting a Mac Mini and then buying a 2TB Firewire drive.