I'm severely disappointed in online play. Not only is it laggy but in order of popularity, everyone plays Scorpion, Sub-Zero, Smoke, Raiden, Cyrax, Sonya, and Noob.
It seems that most people only play characters that rely heavy on teleporting and/or severely incapacitating moves (freeze, spear etc).
I have resorted to just playing Quan-chi, Nightwolf, Sindel, and Jax - simply because nobody does (and the fact that I just get my ass kicked might be why).
Combos are nearly impossible to pull off, although some people seem to be able to routinely. Special moves are about a 50% success with this lag. Seriously, no word on a patch coming?
I ALWAYS give a 0 rating to anyone playing scorpion, and if a king of the hill doesn't start getting variety in his character choice, I give low scores too.