this guide to the Sartharion fight from the guild <My Little Pwnies>. It illustrates positioning of the Obsidian Sanctum fight using, well, stuffed animals as visuals.
As you can see from the image above, the guide writer used a bear tank, two cat druids, a Moonkin and a Resto druid, but that's just to show tank, melee dps, ranged dps and healer positioning. I couldn't tell you if the strat is accurate, it may just be all for laught, so you may want to check out the more popular strat sites around the net for the lowdown on the entire encounter.
The next promised strat guide from this guild is Kel'Thuzad, played by baby seal with a knit Dr. Seuss hat. I can't wait.