Just for kicks, once you get a maxxed SnD going try 4+n/4+r (without glyphs). That should start you off.
You know... Aldriana made a great point on the EJ thread about WotLK: Paraphrased as "Mutilate makes good rogues good, and bad rogues look bad."
It's up to us which we are. Really, there is not going to be a simple Muti cycle that's easy to optimize DPS like we had in Combat. What I'm finding in my experiments is that it's a lot like being an affliction lock where you're trying to juggle several different timers (HfB, SnD, Rupture, D.Poison Stacks, etc...).
Best advice is:
Aldriana wrote:
1) Keep HFB and SnD up.
2) Maximize rupture uptime.
3) Envenom as much as you can without violating the first 2 rules.
Good luck out there!