Welcome fellow Rogues!
Here are the recommended talent specs as provided by Aldriana over at Elitist Jerks. If you have never been to the EJ website, then I strongly recommend browsing their forums.
Recommended Assassination Spec 31/2/3
My notes: Most of my time using a Mutilate build has been spent in battlegrounds and arenas so I cannot say much about raiding with this setup.
Recommended Combat Spec 2/31/3
My notes: My preferred raiding spec as well. I have raided as Combat since my first forays into Karazhan. I like Improved Sprint and Blade Twisting over the other filler talents if focusing on pure PvE content. Blade Twisting acts as pseudo Crippling Poison as Combat Rogues will normally have Deadly/Instant poisons equipped without weapon swapping. Improved Sprint is even better for getting OUT OF THE FIRE especially if snared which I get the feeling will happen a lot in Cataclysm content.
With the loss of Armor Pen, Rupture is back in the Combat rotation along with the new Revealing Strike ability. So those that wanted a more interesting button pushing style for this spec apparently received his or her wish. A bit of frustration may be found with juggling combo points by working RS around a glyphed Sinister Strike. RS grants a 15 second debuff on the target so it does not have to be used immediately before an Eviscerate or a Rupture. For example a rogue with glyphed SS with three combo points and no RS debuff on the target procs an extra combo point on the next SS for a total of five combo points. Now the rogue loses the combo point granted by RS. This can be avoided by using RS for the first combo point leading up to a rupture or eviscerate.
Recommended Subtlety Spec 3/2/31
My notes: I have never given the Sub spec a try, even when HAT was bugged in our favor in the early days of the WotLK content so therefore I cannot give any good personal insight to this spec and its rotation cycle.

