With all of the healing DPS meta discussions going on, it got me thinking of Disc Priest in WoW. I think it would be fun if FFXIV added a job that works under a similar mechanic.
For those unaware. atonement healing works like this... The healer has a few weak healing abilities that apply a buff on an ally that lasts for a set period of time (in wow, it lasts 15 seconds, or 10 GCD's). While that ally has that buff, all damage done by the healer is converted some % healing to the person with the buff. This works pretty well when you can apply atonement buffs to a large number of people and then spread out DoTs, resulting in pretty good AoE HoTs. They also have long CD, high damage abilities that work like long CD heals.
It's a very unique playstyle, and I think it would fit well into FFXIV. If the devs are looking for new ideas for a healer that doesn't just take one of the current healers with a new skin, I think this would be a good one.