try this combo , auto-keyboard (murGee) and macro , set your murgee or other auto keyboard program to repeats macro or u can do that by clicking on it if u are not lazy :), and enjoy it 
btw use macro toolkit or other addon
/castsequence reset=target Howling Blast,Plague Strike,null
/castsequence [combat] reset=0.3 0,0,0,0,0,Plague Leech
/castsequence reset=0.3 0,0,0,0,Frost Strike
/castsequence reset=0.3 0,0,0,Obliterate
/castsequence reset=0.3 0,0,Soul Reaper
/castsequence reset=0.3 0,Horn of Winter
/castsequence reset=5/target Howling Blast,Plague Strike
/cast [combat] Pillar of Frost
/cast [combat] Empower Rune Weapon
/startattack
before start atack u can type /use (if u have some trinket or u want to use some potion)
tell me if u like it
lol its nice to know when you got it from Quentin Rademaker 
hehe who said that i cr8 macro ? i just share it with people who didnt find it yet , coz it helped me so much in raids and i like it
for me it doesnt work much, what is the correct talents i should be using for this?
Sorry, this macro is not optimal.
am using plague leech and runic empowerment talents what is inportant for this macro , and make sure that u set program correct , set it to click every 30 ms , like that u will not lose too many procs .
on dummy u can do more dps manually than with macro (not much more maybe 3-4 k) but in raids on bosses where u have to run , move etc u will do more dps because when u are doing all that things your hero will still fight for you and u will not lose your dps like if u go manually