Nothing's really changed, just new content. Run Inferno Act 1 over and over again until you get decent DPS, then move on to Act 3 for mob density (Alkaizer route is popular). That's about it... keep killing the same shit till it drops a pretty item, sell on AH, profit, shop, etc. You'll start to see better drops and stat rolls too as your Paragon level increases, at least in my experience. But first thing I would do is hit up the AH and find the best upgrades I can afford, farm and sell more items, get more DPS, then when you can 1 shot everything in Act 3, you can try out the Alkaizer method. I personally run quest 3 up to Seigebreaker. I've never really found anything good from doing the last half of Act 3 and always found it tedious anyways. My favorite spots in Act 3 though are all the extra barracks/underbridge/etc. and of course the ice caves.
Or buy a Goldskin with 100% GF, stack GF on other cheap gear, and run Act 3 Hell all day lol.
In sum, Act 3 is where it's at.