I didn’t get too much of a chance to test this out during beta (although I did notice NPCs and my soldier being a little squishy) but there have been some pretty significant changes behind the scenes on how tanking will work.  Now I don’t so much mean the agro part of it but the mobs you’re trying to tank have been changed.  They hit harder and crit for higher percentages making it more important to keep them on the appropriate person.  To help combat this, Guards, Champs, Captains, and Wardens all get bonuses to their crit defense as a passive skill however they are not all equal as the bonus is tied to the class, the stance (for champs), and the size of your shield: (Dev Diary Here)

  • Guard with Heavy Shield = 10%
  • Warden with Warden Shield = 9%
  • Captain alone/with shield = 3%/5%
  • Champs Glory Stance = 3%
  • Champs Ardor Stance = 1%
  • Champs with shield (Heavy/Normal) = 5%/2%

So, looking at this your best statistical tanks will be Guards, then wardens, then heavy shield wielding Glory stance champs.  And from the comments on the beta boards, fervor tanking champs get hit REALLY hard and are not viable options.

I really like this change as again, it makes the game more complex – you can’t just toss more DPS on the fight to win it.  This was one of my biggest issues with most of the Moria content, you could out dps any content and not have to really think too much about it, not to mention some fights were just pure DPS races.  You’ll need to have a tank and work together to make sure that tank keeps agro – minnies, RKs, and hunters will most likely get hit very hard.  I think it also helps champs define their roles a bit better – if they want to tank, they need to trait and equip for it.