Turn off all the buffs in the Buffs tab that you don't apply yourself. There will be loads of things buffing your DPS ridiculously, because the default spreadsheet settings make it so you're in a totally optimal for rogue dps 25 man raid.
Edit: Your rotation looks off.
stealth
HFBx3
Garrote
Snd
Mutx4 ~~~??? You should only need 2 muts. Your crit on mut is 43%, and ruthlessness chance after freshener is 60%. Only in terribly rare cases would you need 3 muts, but never 4. Max your last point in ruthless
Env (Refreshing SnD)-
Mutx4 ~ again, 2 and very rarely 3 muts are required
Rupture ~ Check out your Rupture damage, then check out your Evis damage. Rupture will probably be marginally higher, but Evis can get crits and also benefits from Sunders, Faerie Fire and Curse of Recklessness. You may want to invest points elsewhere in the tree and drop Blood Spatter.... It's said that 5Env/5R is the best, but I had similar weapons and gear to yours and I was doing higher dps with 5evi/5evi.
rinse and repeat keeping HFB up every 29 sec.
Talents: You can drop Vigor. When I was a fresh 80, I noticed I was doing higher dps by taking Imp. Evis and Quick Recovery or Fleet Footed (depending on how much grinding you do) and using wound/deadly instead of instant/deadly and dropping Improved Poisons.
Weapons: Spend 250g and get two LPCs. Your abil dmg will lower some, but you will see tons more focused attacks and poison procs which will boost your dps a lot.
Before you take any upgrades, plug them into that spreadsheet with ALL the correct parameters.
Edited, Feb 27th 2009 10:45am by morgorg