The update will include "a myriad of much needed fixes and tweaks to the experience... including a metric ton of small, but annoying bugs and gameplay issues that we've identified and earmarked for eradication."
Additionally, the following playlist updates will go into effect, as detailed by Bungie's "urk":
SWAT is taking one in the face (being removed) and the weighting for all other gametypes will be adjusted to fall in line with voting data. Expect -- surprise, surprise -- more traditional Slayer offerings to appear.
SWAT gametypes that are removed from other playlists are being incorporated into their own, unique playlist with adjustments made to modes and maps based on voting data (farewell SWAT on Hemorrhage, you sucked and everybody hated you).
Powerhouse will now feature several more gametypes, including 1 Flag and Stockpile. Because Powerhouse is awesome and we don't get to play it enough.
Rocket Race is being added. You win by staying on the Mongoose and racing to the checkpoints. (Oh, who am I kidding, you're just going to hop off and try to assassinate people, aren't you?)
Big Team Battle
SWAT and Classic are being removed and the frequency of Snipers is being reduced based on -- you guessed it -- voting data.
Boardwalk and "Pro" options are both being removed. Default Zealot is being replaced with Arena Zealot, a map variant which features modified initial player spawns and a soft-kill zone in spaaaaaace.
"Pro" options are being removed. Arena Zealot (details above), is being added.
Credit earn rates for Gruntpocalypse are being reduced to fall more in line with other modes.
Since when did you have to be a teenaged Asian kid to understand multiplayer game types?
I was about to write a serious reply, but then I read your profile name ; p