The changes to the armor, be it set or non-set, are almost exclusively adding strength, on the warrior sets at least.
Sometimes the strength gains are fairly substantial, too.
Even shields seem to be getting in on the action.
With these changes, tanks who were worried about their raid or badge gear being outmoded won't have to worry as much, they should carry over into the new tanking mechanics.
This change makes hats like the Battleworn Tuskguard, already an exceptional tanking hat, maintain a nice threat edge and gain more value for soloing with the new scheme for threat via DPS.
While the SBV may seem to have taken a hit, 2 strength = 1 Block Value in the new order of things, meaning that these legs still provide it.
However, with the changes you can see that the Unwaverings no longer totally dominate the Destroyer pants for threat.
Some of the best threat gloves around stay some of the best threat gloves around.
And why should it? With the new strength added, this threat tanking belt gets, if anything, even better.
My hit chest (I passed on Destroyer) stays worthwhile for pure threat thanks to the added shield block value and DPS increase from the strength.