Really depends on the player and the guy mastering the Raid Tool. If they are fully supported, they will do very good, but not good as the usual top parsing suspects for many expacs to come. Seeds of Destruction expansion opens up the game for Wizards and Mages. But like any class in Game - I've seen Wizards doing godly on parses and I've seen close to BiS/AA'ed Wizards doing Meh. Also depends on the fights (Resists, Duration etc.)
Until the guild hall becomes a thing your best contribution to making raid targets dead faster is to get on early and help get people to where they have to be. Your DPS may vary from target to target, but it's not dying either way until your guild gets there.
Wizards are God's at all times and only get better as expansions come out. Don't listen to these fools.