something to remember is that there will alway be a level of input lag with every game, this is because there is an amount of time required for the controlers wireless signal to get to the ps3, then the ps3 to process it, then send the visual representation of your movement to the screen, then your screen to process the signal and finally display it as a graphic on the screen.
if all of these individual eliments of the process can be reduced to their most efficient level it is likely that you will not notices as the total amount of time takes is so minute.
However Dice clearly had a lag issue with the PS3 processing, which resulted in a delay in sending that information on to the screen. Now they have provided the ability to turn off Anti Aliasing you can opt to reduce the amount of processing the ps3 does and in turn reduce the delay at this stage in the process........
BUT...... because we all know there is lag with the game, many people have failed to look at the other areas of the process which could also be causing lag. Namely their screens ability to quickly process the signal its recieving. Leaving them to believe that the game is still to blame and Dice to be responsible..... I disagree.
I have every image enhancement feature for my Samsung 40" tft turned off (reduces lag related to the screen processing the image), I have the audio being sent unprocessed from the PS3 via optical to an external sound processor (reduces the potential lag from the ps3 processing sound), I have anti-ailiasing turned off in BF3 (which has reduced the load put upon the ps3)
different people are sensitive to lag in varing amounts, this combination of settings has greatly improved my experience and i would say i do not experience any noticable lag any more. As a bonus, the type of Anti-Aliasing that Dice implemented makes the textures slightly softer/fuzzy, by turning it off i feel that the image quality has actually improved as the textures a crisp and clear.