As the game progresses, SF4-esque OSes have started showing up, as far as I'm aware mostly with Ryu (Tokido, for instance, does jump heavy -> OS parry; if the opponent blocks and v-reversals, parry comes out and he punishes). A friend of mine has been doing jab -> jab (parry) as an answer to Chun's IA legs (double jab on hit, jab to parry on whiff).
Share your OSes if you have em, otherwise let's talk OS mechanics in this game.
1) Jump-in OS. Oldie and a goodie. I haven't tested this (seems less prevalent with the lack of invincible backdashes) but a Ryu friend says he does jump-in OS hk.tatsu vs Dhlasim's teleport.
2) Chain priority. The interesting one. You can't hide a normal (e.g, sweep) input anymore, but V-skill works. For instance, jab -> jab (skill) vs Dhalsim's wakeup means you'll get jab -> run if he teleports, otherwise jab - jab if he blocks.
howard.roark says it can be done with specials, though very briefly trying out his lk.tatsu OS I can only get jab (lk.tatsu), no luck hiding it in the chain i.e jab -> jab (lk.tatsu), lk.tatsu just comes out after the first jab.