What is this other playstyle that focuses on stam/mastery? Never really heard of it talked about in any serious manner, nor can I imagine the playstyle being wildly different. While I have a separate stam/mastery set, it's not much beyond swapping to a 2 hander, using stamina trinkets and swapping my helm and a couple other items of gear. I also play exactly the same as I would with my regular tanking set.
I also can't help but imagine a full stam/mastery set to be a complete mana sponge, taking an absolute ton of damage and draining healer mana. Sure, you'd be able to survive more burst damage, but is that really necessary? I can only imagine it being useful at the very start of progression, when undergeared, so would only really be useful for super hardcore guilds.