Battlefield 3 is set to receive an update that will address a number of known issues, and the contents of the patch has been detailed on the Battlefield Blog as additionally some of which is shown below. A few of the fixes relate to the Playstation 3 version of the game which weve edited out it has no relevance here, but the Gun re-balancing list is as follows.

M416: First shot and horizontal recoil slightly increased. This should make the choice between M16 and M416 more interesting again.
L85A2: Slightly reduced horizontal recoil.
AUG: first shot recoil slightly to increase weapon controllability.
FAMAS: Slightly reduced horizontal recoil.
G53: Vertical recoil reduced to make this weapon more controllable.
QBZ-95B: Slightly reduced horizontal recoil.
LSAT: Hip accuracy has been increased to highlight the weapons role as a highly mobile LMG.
Type88 LMG: Recoil has been decreased to make it a viable option when compared to the M249.
M5K: Increased horizontal recoil and decreased vertical recoil to focus this weapon as a high damage, low control PDW.
UMP45: Decreased fully automatic fire to differentiate this weapon from the PP2000.
MP412: Increased its accuracy to better distinguish it from the .44 Magnum.
M26: Increased aimed accuracy to be in line with the other shotguns.

There are a number of Map fixes and other issues addressed which will go live on November 27th, 2012. When starting the game, you will get a popup notifying you that Multiplayer Update 5 is available. It is not mandatory to accept this, but advised that you do so. Otherwise, you can find Multiplayer Update 5 both on Xbox Live Marketplace and in the in-game store as a manual download.