Again I don't think we'll ever top meters in serious content, but my guild's top casters are equally geared and I have no problem keeping up.
We are definitely NOT mid Ulduar.
Do we scale equally? Absolutely not, and we won't see anything change as far as our damage is concerned until Cataclysm. Half of the problem is in our talent tree, the other half is the very solid class mechanic built around our spell priority, which locks us out of ever having any type of 'Nuke'. Once they implement the talent changes in Cata, I hope to see builds and talaents that scale through end game content like Mage/warlcok trees.
But again, just my little ol' opinion.