Shadow tanks are currently very nice assets for each WZ. Great for 1v1 (such as after surprising a solo defender to cap a node) and they are the best node defenders, hands down. Also, when a team overpowers a node, shadow tanks can simply delay the whole team enough for the reinforcements to arrive (stealth, wait for the cap timer to hit 6 seconds and overload/force wave). They are the second best ball carriers in Huttball and the best ball carrier killers (pull). All of this is true after 1.3. Before 1.3 I think they were "the best" class for PVP.
With all this said, I don't know how much resilience will effect. But current changes to force wave/overload benefits the shadow/assassins better than sorcerers (since as a melee, they were already facing their opponents, now they have 15 meter range on top of it). Plus, they got buff in other trees for PVP. Previously, there was 1 skill tree and 2 different builds (tank with dps gear and hybrid), now there are more variations available.
I would not call the tanking role out just yet.