EDIT: As a followup, I've been able to kill The Butcher with only 9k life using glass cannon and stacking as much Attack Speed as I can. It's a little RNG, but if you can get your Templar to tank him long enough (get him stam!) you can kill him very quickly. You need glass cannon for Act 2 onwards, otherwise you won't be able to kill the rest of Inferno. Unfortunately you have to time Smoke Screen with a few chains with this method, but he dies so fast it shouldn't be too bad.
So I totally missed this until I was fighting Nightmare Mode Diablo. And I feel dumb about it. Since others will make this mistake since I did, you will want to turn elective mode on at some point while playing Diablo 3 so the game doesn't lock certain abilities in certain slots. Elective mode lets you use any ability in any slot, broadening the possible ability combos you can equip.
Since this isn't painfully obvious (and it should be, since you need it), I hope you Diablo 3 players find this post.
I've been a Diablo fan for some time. I enjoyed the first game but didn't play it a great deal. Later, in 2000, Diablo 2 consumed me for months at a time when I was but a snot-nosed middle school student. So Diablo 3 has finally arrived in 2012, 12 years later. Does it live up to expectations? So far: yes.