Yes, yes it is. And sometimes, its so random it pisses people off.
My guild is known for its bad drop rate for caster items. We've seen the Ring of Rapid Ascent twice since ICC was released. Once on normal (our very first kill) and once on heroic. We've seen the DFO about 4 times since killing (both heroic and normal mode), and don't get me started on Lady's Brittle Bracers. First time they EVER dropped was last week.
Yes, our casters are undergeared compared to our melee. Our melee are deing alot of the stuff, going offspec and much more. We see nothing but Conq and Prot tokens every day. Vanquisher is a 1 in a million drop for the Heroic Token. With Caster items on the low down, most casters are putting up the items they don't see much of on their loot lists and putting tokens at the bottom.
So melee get the tokens first, gear that always drops and the other good stuff.
Yeah, being a caster is fun. This is where I wish the SEED idea was true, cause I will gladly tell our GM he as a bad SEED. :(
In other words, @#$% random loot.
So, whats your luck with loot?