Team make-ups are fun and challenging. There is no correct combo for a team its what you the player wants to try. Ive done shaman and holy pally always nice for that bubble. Done priest warrior once again great dps and a heal button for a non healing class. Then done rogue druid always fun to be able to use stealth on both chars. So basically its what you think would be a great combo ive always found as long as you team consists of a healer you cant go wrong cause you will always get into situations that consist of being healed. Like now im doing 5 boxing shammies and 5 boxing hunters. Shammies way way over-powered, and on the other hand so isnt 5 hunters. So in your question mage priest is a really good combo you have cc heals and if you spec shadow your dps will be insane for the long haul.