Well recently i started on a mage, which seemed like a good idea. But to be honest casters are not on the luvin list if you look at the whole lvl 255 thingie. Most classes scale very well, but those are mostly physical damage. Now i haven't been all around the world with this mage yet, but from i have seen from duelling the casters with my rogue, is that they have really low damage compared to me. Also my paladin which may be the lowest dmg dealer ever have better damage than casters.
What i suggest is a ring, trinket or something like that, nothing major to be added in BB. This item would only be for the 3 major caster classes (warlock, mage and priest) and should contain around 500-1000 spelldamage (not sure about this, have to look up on how well physical dmg classes scale). The item lvl would be 255 and the price should only be symbolic.
With this casters have a greater chance, and we would see more casters around on the server instead of 30 rogues, 15 warrs and a shaman :P

The reason for this is because when casters level.. they don't get spell damage, when leveling.

i know that is why they come off much weaker than other classes who do infact scale their dps. I know that on blizz casters dont scale with lvl either, but the gear differences make up for it. In retail casters gain a little more dps etc from gear than other classes to make up for their stats not giving more dps :P.
That was why i came up with the idea
Giving casters a few hundred more spelldmg would bring them up to physical damage classes' dps. Which is where they should be.

yeah were gonna try work out a way to give warlocks, shamans, paladins, priests & mages.. about 2 or 3 spell damage per level.