Dragon Kick was invaluable in T13. It was already mentioned in the last live letter that we will have more magic mechanics on the horizon. If your group doesn't have a DRK for Delirium Blade then go with MNK. Battle Litany is great and all for offensive utility but if your group is dead there's no point in having extra crit. Sure once you have content out geared DK/Mantra will be less useful but by then you could have MNK and DRG both leveled and geared and just switch.