If the Wizard was ever overpowered (under heated debate apparently), then not much has changed. The Arena Wizard still has the best mage abilities, the best training (e.g. no triple-cost, and cheap access to arcane and his choice of element), and the best (only) built-in ranged attack spell - which happens to also be the only built-in ethereal attack, and can't be removed if you want to protect your Incorporeal creature (e.g. Invisible Stalker). None of that changed with Domination or Academy.
I did notice that Academy cards that are most useful in Arena tend to help the Beastmasters more than the Wizard (e.g. lots of useful creatures and Beastmaster-specific equipment). This helps the Johktari Beastmaster in particular become "less bad," but doesn't make the Wizard worse. So, sure, the Beastmasters have been pushed in the right direction relative to the Wizard, but the Wizard hasn't really gone anywhere, and the problems (if any) with the Wizard are still there.
Now, before we say that the Wizard can do everything better than any other mage, that isn't quite true. There are some things that some other mages can do better: the Straywood Beastmaster and Necromancer are better at summoning swarms; and the Druid is better at controlling the board state through hindering and the "stuck" condition, and can extend her spell range so she can turtle in a corner while affecting the other side of the arena. But the Wizard can trump any other mage at solo (e.g. armour up and go melee), "one buddy", and "burn" (e.g. hurling attack spells while pinning the opposing mage), plus has exclusive access to mana/action denial, and can build the ultimate toolbox of incantations, enchantments and attack spells at standard and/or discount cost (e.g. can include more "staple" utility spells than any other mage). So... basically, the Wizard has none of the drawbacks that other mages have. That will never change unless it is added to the Wizard's mage card (e.g. make something cost triple, or add a drawback to Voltaric Shield or Arcane Zap).
And all of that ignores any imbalance with Wizard's Tower. If you gave every mage a "mage type only" card that was on the same power level as Wizard's Tower, that's fine... but the Wizard still gets all the other advantages above, so it still wouldn't be even.
I think the only thing Domination did was add [mwcard=MWBG1E01]a counter to Teleport[/mwcard], meaning Teleport isn't quite as powerful as it was pre-Domination. Since Teleport is level 2 Arcane, it gave more advantage to Wizards than other mages - so I guess that pushed things slightly towards balance. But Domination also brought [mwcard=MWBG1A03]Hurl Meteorite[/mwcard] and [mwcard=MWBG1A02]Dragon's Breath[/mwcard]... so... it's probably a wash.
In other words it's hard to balance mages through adding cards when the out-of-balance aspects are written on the mage card unless those spells are "mage type only." And adding a bunch of "mage type only" spells hurts the overall flexibility in spell book building because it means those new mage type only cards are intentionally overpowered by design and become must-includes in order to make a mage competitive relative to the Wizard.