Just for the record regarding patches, when MW2 was first out the PS3 version got some updates before the 360 version. The main patch that reduced lag was out for several weeks before the 360 one from what i recall. The 360 version of MW2 was also hacked like crazy compared to no hacks on the PS3, the care package glitch was also hardly abused on the ps3 compared to the 360.
360 players were constantly thrown into 18player ground war games on Rust(smallest map) with players smashing them with ac-130's from above.
360 players also had to endure wall hacks, auto aim, players shotting ac-130 rounds from their guns and rapid fire RPG's.
W@W right now on the 360 is unplayable for the most part with 95% of games having players with god mode or some other hack.
MW3 pre-orders mean very little this early and when the game is closer to coming out the pre-orders for the PS3 will go up.
I'm not sure about CoD4 on either system or W@W on the PS3. Black ops 360 and MW2 ps3 have very little hacks going on right now based on the games i've played.