If they were to make the change i listed above to butchers bock it would be to make the rotation more interesting or to give the skills a use not to make them do more DPS or whatever.

Currently emnity doesn't matter and i think thats a good thing. If you make emnity matter than your basicly still a tanky DPS, but a tanky DPS that could potentially slow all the other DPS down if you are under gear or preforming poorly. Making the role a more dramatic effect on a team than pretty much any other role. As even healers bench marks as of current content aren't being able to heal really agressively, but more finding windows where they can optimize thier dps. Plus making emnity matter even more would also unnessarily evelvate classes like ninja, and hinder classes like paladin with the current game in mind.

However, making the emnity combos part of a given rotation or giving them an extra feature would go a decent way to making tanking more interesting.