I'm having the same problem at 80, my swipe used to crit for 5k ish, now it crits for a meesly 1500 ish and next to no threat. What people also seem to forget is that T10 2 pc provides 20% increased damage to swipe, so as soon as you take that off, all these numbers your seeing at the moment will be even less!
Druid tanks have been hit big time with the nerf stick, its gona take us months to recover from these nerfs, until at least the top tanks are at 85 and are complaining loudly on the official forums