@scotty85 has one, he may stop by and say more.
Basically, it's not as much chit-chat as you may think.
It involves a card that allows you to change the start up sequence on an HTC just enough to gain entry.
The start up sequence on a Samsung is rather different and their locked bootloader is radically different - if a gold card method could be devised, I'm fairly sure that it would require a complete redo of everything that has gone into years of finding and building out this exploit for the HTCs.
It's not something that would happen overnight - unless someone has already basically completed it, so far as I know.
Getting a root friendly phone is always the best choice in my opinion but that's just me.
If you're that sold on Samsung, fine, great, but it's not the only Android on AT&T and best is relative to your needs.
Best luck!