the best way make a start on mage group utility would be to give us a mana aura. mages had it in W3, and i think an aura for +mp/5 would actually make us consider duration fights. the reason they aren't gonna do it is because shamans have such a thing and paladins too, though not as an aura.
allowing us to attack sheep without breaking the effect and without the healing would be another "fix" back to way things worked as described by lore, and would possibly give us a little boost in the right direction for pvp (warlocks have been able to do this since launch, so why not us?)
mages need white damage. dots possibly, but the LoS exploitation is a serious pvp problem for classes who must stand in one spot and cast for seconds at a time. a real fire dot would work miracles for pvp los issues, and something like creeping cold could be dreamed up for frosties. aside from oomkin (which is really only 1/3 of the class, not ALL druids), mages are the only class in the game who are rendered useless merely through consistently taking damage -- rather than requiring a real CC method to lock down. hunters are, for all intents and purposes, spell casters (ranged dps) but their damage cannot be stopped short of something that causes lose of control of their character, and even then they still have pets. bringing mages closer to this sort of performance wouldn't require that we do more damage, our base damage per spell could be decreased to make up for a gained ability to actually DEAL it in the first place.
dampen/amplify magic is, right now, even more useless than detect magic (which, i'll point out, they removed and gave to everyone for free, essentially) was. in the manner of paladin buffs, i'd like to see these two spells changed in a way that makes them not only worth using, but possibly with offensive uses as well. i can easily see this akin to the paladins' judgements. increasing the spell damage taken by targets and at the same time reducing damage taken by allies (and decreasing/increasing healing received) could allow mages to finally be useful to other classes than themselves. i believe this sort of functionality is what blizzard had in mind with improved scorch (in a raid setting) and i'd gladly up imp scorch for this kind of ability.
aside from counter spell, mages have no serious defenses against spell casters in the way shadow priests and warlocks have. mana burn should have been a mage spell all along, but whatever. spell steal was a great first step, but considering how outrageously expensive it is (compared to purge, dispel, devour magic, cleanse...) i think it wouldn't be at all unreasonable to ask for the mana cost to be reduced to about 20% of what it is now. if they did that, i could forgo my next request. which is to make improved counter spell automatic (remove the talent and just add that behavior to all mages' CS).
because, really, we don't have a wide variety of spells. as a pure caster class, it should be worrisome that only druids have a smaller spell selection than we do, but they have feral forms to make up for it whereas we still can't sustain top dps and neither do we have any definitive utility or CC role. warlocks have more CC options and capability than we do (roughly three or four times the number of abilities, depending on how you count your fears), and despite the ubiquity of humanoids, beasts and dragonkin, sheep is just not the most important or even most powerful CC method. disappointing when you remember that the mage class was officially defined as utility, CC and magical dps at launch...
as long as i'm wishing for the world, i'd also like to see the water elemental become a permanent pet for all mages. perhaps obtained somewhere in the middle levels. obviously the elemental's damage output should be reduced in this case, and i'd like to see other abilities granted to it (why not? hunter pets and warlock pets have almost as many different abilities possible as druids have spells!), but this doesn't mean it would have to be a tank either. it's just pathetic that frost mages only have three abilities without a cooldown, one of them is channeled and another you don't get till level 66. sure, they're decent enough abilities and some are important for all mages, but is it too much to ask that my class require more involved thought and action than i could easily program a bot to do? i'm about to have to replace my "1" key while "2" - "=" have visible dust on them (well, not now that i pressed 2 and =).
and yes, i'm even irked about molten shield. warlocks who's dots gain massive bonuses from +dmg, got a self buff that gives even more +dmg on top of augmenting their outrageous endurance (a warlock can life tap huge amounts of mana from just a single lifebloom, for instance, and i don't any reason for them to have special treatment from a healer on top of their mana generation capabilities). the damage shield portion of molten shield is just pathetic. you'd deal more damage if you got a free melee swing with your equipped weapon every time you were hit. the reduction in crits received is a decent enough effect, just far too weak to really be worth consideration in pvp where our life expectancy is approximately the time it takes a hunter to press three buttons. and, really, pvp is why that 5% crit reduction is even there. the crit rate increase is also nice -- who can complain about extra damage. except when it's a measly 3% and what mages really need is reliable damage output, not spikes on their threat meter. for starters, mages' strong point is against melee attackers already: what we really fear are ranged attackers, and last i saw, molten armor didn't do anything to them. i'd gladly trade my molten armor to any warlock -- i need that 20% extra healing while i'm AoEing in a raid/group, thank you very much, and it's much more important for me then than it is for a warlock who just wants to steal some of the healer's mana.
sure, i'm whining. sure i'm green with envy. but mages have a right to be, i think. and in that case, it's not whining or jealousy at all; it's an objective observation.