We are also moving towards Meta Packaging and when it comes around we will probally develop a new way of doing dependencies altogether. If all you do is install everything from RPMs, everything works like a champ. Something needs to be done differently, and I shouldn't have to create RPMs of everything I'm going to install to make it work. Yeah so far so good, but no one bothered to make a distro like that. Give me a break.
Someone make a distro with ports tree or something.
And btw, SPK sounds nice. You can rsync your local tree to the central one, and whenever you like just rebuild one of the programs for which there is a script in the tree. You can uninstall the installed program just as easily. It may not be exactly what you are thinking of, but its definately worth checking out. SGI enforces a fairly strict naming system which lets you very quickly select groups of packages for installation, removal, or update using simple commands.