Theo pretty much said it all up there. Only thing I can recommend is that either you or him pick improved expose armor. When I play with my rogue pall we usually do the following;
Me: premeditation, (shadowstep if the target is AOEing), cheap shot, 5 combo point expose armor, blind partner
Pall: premeditation, shadowstep, ambush, (SS/shiv), kidney shot, blind partner if he trinketed out of my blind
With some timing you can pull this of at a pretty fast rate, and since you have the element of surprise on your hand (specially vs AOE'ing peeps, they don't expect you to get the opener when they're spamming AOE) it can work very well.
Our main counters are paladin/warrior and restodruid/anything. When there's a paladin healer we can usually throw a well timed kick to stop him from healing his buddy as we nuke him down. The problem is that warriors have too much HP and armor for that. Still, we manage to beat paladin/warrior combo's about 50% of the time by just nuking the paladin into his bubble, getting the hell out and restealthing, nuking the paladin to death and then 2-manning the warrior (this is at times incredibly difficult, but usually one of us bashes away while the other goes and restealths). Combinations with a restodruid are pretty much impossible to beat, we lose those 90% of the time. We only win when the druid is too late with trinketing out of our double blind and we manage to down his partner before he gets his instant full heal of.
I can see ShS/mut work out, but you will have to be the one with imp expose armor in the setup. Just hope that in the chaos when you open your buddy can find the chance to sneak up to the target you're slapping.
On a sidenote, the power of double stealth is NOT to be underestimated. Me and my pall usually spend ~10 seconds discussion our strategies while the other team frantically jumps around and AOE's.
Edited, Jul 13th 2008 5:51pm by Mozared