I plan to stay Engineering / Mining.
#1 both are profitable and help fund me being a tank. Mining also helps grind Engineering when the mats are sky high early on
#2 500hp free is nothing to scoff at. Several of the very expensive crafting professions can't even claim 500hp in value from start to finish.
#3 I've always enjoyed Engineering....yes I absolutely agree its weak right now. However, Blizzard has always buffed Engineering when its weak "eventually". I fully expect this to continue.
#4 Instant cast grenades rock soooo hard.