Looks like EPIC want's to finnaly give us what we have been wishing for. So lets all get together online next month and try it out.

Who's with me on this?

Improvements

Title Update 6 makes these new improvements:

• Adds a new public multiplayer match option called Social Xbox LIVE (aka player matches), open to anyone who owns all downloadable maps (that is, All Fronts Collection). We'll be having a promotion that will dramatically reduce the cost of the All Fronts Collection.
• You can join Social Matches in progress and can quit any time without penalty, although players who quit a match early don't receive earned experience (XP) from that match.
• Social matchmaking lets your party join a match in progress. If a match is not found, your party hosts a new match, filling any empty player slots with bots.
• Social Matches automatically cycle to the next map without further matchmaking.
• Teams are rebalanced between matches based on XP level without splitting parties.
• If you quit, your spot is taken by a bot until a new player joins the match. That new player can join while the match is in progress.
• If you join a match in progress, you are assigned a team based on XP level and party size.
• If you join a match in progress, you replace a bot at the earliest opportunity: at the first bot's death for respawning game types (for example, Annex) and at round completion for Warzone, Execution, and Wingman.
• Social leaderboards become part of the War Journal.
• Renames Public Matches to Ranked Xbox LIVE Matches to differentiate these from Social Xbox LIVE Matches, and adds some improvements to these matches.
• Improved host selection using bandwidth testing and previous hosting data has been added.
• Before the match begins, teams are balanced based on XP without splitting parties.
• Renames Private Matches to Custom Xbox LIVE Matches and makes these matches invite-only.
• Adds the ability to join Horde sessions that are in progress.
• In Social Horde, you can join a session in progress through matchmaking and you are able to continue your session from the last wave you failed without starting over.
• In Ranked Horde, you can join a session in progress only through invites.
• If you join a session in progress, at the end of the session you receive the score you achieved during the time you spent in the session.
• Improves the precision of weapon selection using the D-pad.
• Improves client-side hit detection for ballistic weapons.

Exploit Fixes

Title Update 6 fixes these possible exploits, where under certain circumstances:

• Execution rules could be ignored when using certain weapon types.
• On the Subway map, you could get outside of the playable environment by sliding into cover and rolling between a train car and the side of tracks.
• On the Blood Drive map, you could get outside of the playable environment in various locations.
• Players could grief other players on Submission, Annex, King of the Hill, and Guardian games by preventing the objective from being completed while racking up experience. Title Update 6 adds match time limits to each of these game types to prevent this practice.

General Fixes

Title Update 6 fixes these other issues as well:

• An issue that could cause your profile to be overwritten, erasing XP level, and achievement progress.
• An issue that could cause a campaign save slot to be overwritten if you previously chose to continue without saving and then signed in.

Balancing

Title Update 6 makes these balancing changes:

• Changes the Gnasher Shotgun pellet pattern to increase hit consistency.
• Changes the Guardian game type to select the leader based upon XP level (highest to lowest).

TU6 Release Notes 5/17/2010 [Epic Forums via CVG]