Abilities:
http://wiki.ffxiclopedia.org/wiki/Spontaneity (This above all would probably be something specific for when they introduce long cast spells, i.e meteor or something.)
http://wiki.ffxiclopedia.org/wiki/Composure (This has become a staple of RDMing, increasing duration of buffs on yourself is something all mages have wet dreams of.)
http://wiki.ffxiclopedia.org/wiki/Tranquil_Heart (This I think should be WHM/RDM really.)
http://wiki.ffxiclopedia.org/wiki/Phalanx_II (Unique spell that reduces both magic and physical damage taken? As well as casted on others? Yep.)
http://wiki.ffxiclopedia.org/wiki/Gain-MND (Gain/Boost spells grants you additional + stats. Who wouldn't want this? But SE does need to reexamine the stat bases....)
http://wiki.ffxiclopedia.org/wiki/Temper (For those front line enthusiasts.)