Drethoz, we do 10 mans fairly regularly. Had a couple today, and we'll be doing more in the future.
Suicide kings list page is paradigm-swc.org/sk/rankings.html
Basically as someone takes main spec loot, they are dropped to the bottom of the list, and everyone on the raid moves up to the spot occupied by the person above them on the list who is in the raid at the time.
We have a seperate list for tier pieces and regular loot.
If no main spec takes, then offspec (actually specced as secondary) may roll. Then if noone still wants, people who have not specced it as an offspec, but can use may roll.
For example, a healing druid a boomkin and a feral druid are on a raid. A tanking piece drops. The tank gets the piece if he needs it. If he doesn't, the boomkin, who has secondary spec as a tank, gets it. If they dont want it, the healing druid, who hasn't dual specced yet, may roll on it.