Basically i could use a macro that will maximize tanking (for the tank) and dps (for the dps). Heres what i've come up with so far as of just hitting lv 80. Tank DK has 10 epics, DPS DK has 9. Both dps tests conducted using no cooldowns. Ran a heroic and noticed that dps is only 1000 for tank, 1500 for dps. I'm thinking that instead of having the reset=nocombat it should be reset=target instead.

Tank: spec 5/56/10
2204 AP, 82 Hit Rating, 7.65% Crit, 16 Expertise.
/castsequence reset=nocombat Icy Touch, Plague Strike, Howling Blast, Blood Strike, Blood Strike, Obliterate, Howling Blast, Blood Strike, Blood Strike
/cast Rune strike

lv 60 training dummy: 2289.4 dps
lv ?? training dummy: 1546 dps

DPS: spec 0/10/61
3157 AP, 206 Hit Rating, 19.63% crit, 8 Expertise
/castsequence reset=nocombat Icy Touch, Plague Strike, Blood Strike, Blood Strike, Scourge Strike, Scourge Strike, Scourge Strike

lv 60 training dummy: 3150.9 dps
lv ?? training dummy: 2225.7 dps

If anyone has any suggestions please post!