Somehow I played WotlK on Warmane years ago, yet I reached max level, but never tried raids. But since Im playing Turtle wow (And played some time on Sheilun) and now im a raider full time...
I could go back to Warmane, but Stormforge will release a WotlK soon....but with how the recent TBC server they launched now is on sub-1K players (And Shielun has also seen better times player-count wise); I wonder if I should Try Frostmourne or try to go back to Warmane and spam RDF to get Pre-BiS for raids.

And for reference: I have a Arms Warrior on Warmane+A Frost Mage; While if I choose Frostmourne, then I will try Death Knight (Not sure about specc).