I'd rather see them go with a samurai tank in the way SE did Samurai in Bravely Default, that is to say a tank that specializes in counter attacking. In bravely default, the samurai (in that game called the Swordmaster) has a variety of special moves that involve countering attacks, you have a counter when hit with physical damage, a counter when hit by magical damage, and a counter when taking damage from a specific target. The counter lowers the damage you take from that attack and then performs an auto counter attack, thus allowing the Samurai to potentially counter several enemies in a row. I believe they could work something like this with the samurai in this game if they make it a tank by doing something with damage reflection/countering. The only real problem with it is the class potentially having issues with dps as an OT, so it would also need an offensive stance, something like "remove all damage reflection to deal X% increased damage and shorten global cooldown."

One of my favorite mechanics tanking as a sith warrior in swtor and a void knight in rift, were the special moves that allowed damage reflection, they were very potent when used against certain targets and timed right. It's one of the tank mechanics I've yet to see in this game.