IMHO they shouldn't all be equal DPS.. Rangers have Bolas, Mages have Cloak of Fire, Rogues have nothing. If all 3 are equal DPSers, there is no point in being a rogue.. You may aswell just be a ranger or Mage depending on if you prefer cloak or bolas lol. Rogues don't have these kind of skills, they can't hit from distance and they don't have any fancy skills doing crazy amounts of damage every tick to any monster attacking.
Rogues have no great support skills, they can't heal themselves mid-battle, they are just there for damage, this is why I personally believe they should be #1 DPS
Mages, although they have Cloak of fire.. Can't heal themselves mid-battle, and do awful non-skill damage, making it hard to do any sort of solo bosses. This is why I believe Mages should take the #2 spot
And Rangers.. Rangers are an All-Round class and at the moment, and by far the best class on the game in my opinion. Rangers have Bolas.. They can Solo ANY Melee boss. they have great heals in 'Light Heal' (I saw a ranger helping to heal on Spirehoof yesterday, healing around 270 with there light heal which regens very quick). As rangers have no limit at the moment and are an All-round class and not DPS specific, I believe they should take the #3 DPS spot, along with warriors.
As for Druids.. They do awful damage, but there the only class that your likely to see solo Wisp bosses without any pots
As for mages being a support class, you missed 1 skill of your list which, in my opinion, is the best support skill on the game, by a mile :p