From the little experience I have seen with both callings in Expert/Raid environment (Raid as in Expert Raid Rifts), Mages definitely out DPS caster Clerics. This is not to say it's impossible for the reverse to happen but Cleric DPS is certainly lacking compared to all three other callings (which is fine, us Clerics can't be expected to do everything). Lately I have seen some surprising advances in Rogue DPS where it used to be nobody touched Warrior DPS.
DPS: (Inq) 51 (Sent) 10 (Ward) 5
Raid Healer: (Puri) 32 (Sent) 34 (Ward) 0
MT Healer: (Puri) 51 (Sent) 15 (Ward) 0
Tank: (Just) 47 (Sham) 7 (Inq) 12
Inquisicar: (Inq) 51 (Justi) 14 (Sent) 1