A new Modern Warfare 3 patch is launching on all platforms yesterday, according to a post on the Call of Duty forums, and it tweaks quite a few weapons. For instance, not only has the FMG9 been nerfed, but their dual-wielding effectiveness has also been tuned a bit, though they were a bit overpowered anyway.
The fire rate for assault rifles with under-barrel attachments has now been "normalized," the Type 95's spread when firing from the hip has been reduced, and those shenanigans you pulled on "Dome" last night have now been fixed.
Infinity Ward also listed what could be fixed in future patches, which finally includes an updated spawn system.