What sort of advice specifically are you looking for? Regemming, enchants, what gear to look for for upgrades? Advice on talent points? Combat rotations?
That said, I see a few things you could do for optimization: 1 is find new weapons. :P If you're going combat, you really should try to use weapons of the same talent skill. That was you get full benefit from the talent and don't have to split points.
Second is regem. Use the nightmare tear in your blue socket and then use agi or crit or hit everywhere. You have a hit+stamina gem in a yellow socket. First of all, you're high enough hit you really don't need to gem for it, use yellow for crit instead. That little extra stamina definitely isn't helping your dps and probably not going to make you survive getting gacked by a boss.
Also you have a pvp enchant on your shoulder. You should get the hodir one instead. Change your hand enchant to the attack power one or agility or somesuch, as I said you have enough hit that its down the list a bit on needs.
To get a good weapon you could do onyxia a lot of try to pug ToC10/25.
One thing, and this might be controvercial, and is purely up to preference is go with a bloodless combat build. Basically talent eviscerate instead of rupture. Get the evisc glyph instead of rupture glyph etc. On fights where you have to change targets a lot, or on trash it should do a bit more damage. I like it because it's a bit quicker to build to full damage, which is a little more versatile. I arranged my assassination talent points (teir 1)8, (tier 2)2, (tier 3)5. It's also easier in a hectic situation if you fumble over your rotation sometimes like I somtimes do :3 You just keep up slice and dice and eviscerate each time you're full on points. Its competitive because since evisc is your only closer all your talents and glyphs go into that, as opposed of rupture where you put it up, then use points for a much weaker(unbenefited by talents or glyphs) closer then rupture again.
Edited, Nov 5th 2009 7:10pm by digitalcraft