The title of the thread should be changed to something more like "Red Mage: The One Class That Is Impossible To Implement So Everyone Will Like It"
Red Mages can be implemented. But unlike FFXI where they were a Jack of All Trades and a Master of Haste, FFXIV's strict Role system will not allow them to be the hybrid class they so desperately want to be. Red Mage's in XI fit into the Support Role. They were the "equals" of Bard's and Corsairs (and sometimes Summoners) in their ability to buff a group and keep it going over long periods. Sure, they often times were able to fill the Healer role as well, but mostly when incoming group damage and status effects were minimal. They also were the masters of the solo/low man group content due to their flexibility. But in XIV we are saddled with having to fit into a single role. Which role should that be?
Well, we could end up with a Arcanist=Scholar/Summoner set up? YoshiP has come out and admitted that the dual Job from one class was an experiment and in his mind, was not a success. So we can pretty much ignore this as a possibility. (Unless they go and revamp the class/job system which YoshiP has hinted may come with an expansion.)
What we have left is a choice. Do we make Red Mage into a DPS or a Healer? The obvious fit for the game is to make Red Mage into a healer. The game desperately needs a third healer job. But where does that leave the hybrid side of the "definition" of the job? Well, It would allow the Red Mage to be a healer not unlike what the current paradigm of the Scholar healer is. Heal when needed, DPS when you can. Is this fun?
If you go with the DPS role, what exactly do you turn a Red Mage into as a DPS? Typically a Red Mage would be a nuker not unlike a Black Mage, just not as powerful. How do you deal with that imbalance in a game where all DPS are supposed to be made "balanced"? I'm not sure you could if you made them a pure nuker. The next choice would be to make them into the job that the XI devs originally saw Red Mage as, the BattleMage/FencerMage. Red Mage would then be a melee who nuked on combo's and used EnSpells to do their damage. This would more fit into the XIV job system, but would everyone be happy with it? No!
So, While we will get Red Mage (more than likely sooner than later), not everyone will be happy with the Job. The only way to make everyone be happy would to be to redesign the Job/Role/Party paradigm for 3.0 and beyond. The 1 Tank, 1 Healer, 2 DPS (x) paradigm needs to go and the 1 Tank, 1 Healer, 1 Support, 2 DPS(x2) Paradigm needs to step up. Hell I'd love to see the XI 6, 12, 18 person groups come back and XIV's 4,8,24 leave.