So, I've been trying out different builds on my rogue on the PTR. Going with a cookie cutter 15/51/5 swords build taking the new lightning reflexes my DPS is around 500 more. That's still not enough for me to catch up to those doing over 4k sustained now though. I don't know what else Blizz would be willing to buff. Maybe if the dual wielding hit cap was lowered or if they buffed precision or maybe added extra damage to imp SS.
Subtlety still sucks with swords. Hemorrhage still hits like a wet noodle and SS without combat talents takes too much energy and only hits a little bit harder. I tried some weird hybrid builds for PVP on the dummy but, I haven't gotten into a BG on there yet. It looks like mut/prep will still be the best PVP spec. I want a good PVP spec I can play with my swords though. I'm thinking a combat/sub build might work well for that.
Assassination is looking kind of weak but then again, I don't really have glyphs for it (I'm just using my regular ones; Rupture, SS, and S&D), I'm not gemmed for it, I don't have very good daggers (A 1.4 with mongoose and a 1.8 with 50 SP. I just had them in the bank and picked up the only 2 weapon enchants on the PTR AH), and I don't usually play assassination. I think I got the hang of it pretty quickly but, my DPS was about 400 less than with combat swords. I think someone with more experience with the spec and better daggers could pull some similar numbers to my combat swords numbers. I'm not so sure assassination will be much more DPS than combat after 3.1.