A patch will be launched on May 31st , 2012. 2 Days after the Rebellion DLC.

It fixes all the following bugs and makes some changes:

Fixed an issue where sometimes facial movement would not match the voice over if a hitch occurred
Fixed an issue where taking cover in a certain area of Cure the Genophage mission would cause players to become blocked from progress
Fixed Action mode so it will now respect difficulty if set in the main menu
Fixed an issue where the player would always be walking forward instead of towards objective in The Return mission
Fixed the Ultralight Materials SMG weapon mod in multiplayer so it correctly affects weapon recharge
Fixed a rare case where the reinforcement pack purchases could fail and take currency without giving cards
Fixed the issue where users logged off/disconnected during multiplayer gameplay would not log back in properly until their game is rebooted
Fixed the issue that multiplayer Geth sentry turret flamethrower would endlessly repeat audio SFX
Fixed various multiplay maps where a player could fall through the map during multiplayer gameplay
Fixed the issue that using an ops survival pack consumable immediately before death could have no effect. It now works as intended
Fixed the issue so the Falcon weapon in multiplayer no longer sometimes fire blanks
Fixed the issue where enemies who were detonated with a biotic power while in stasis would become invulnerable
Fixed the issue where Banshees who got hit with a rocket launcher would not play the correct death animation
Fixed the issue where joining a match in progress while a Geth prime turret is active leaves the turret there for the remainder of the game. It now disappears.
Fixed the issue when joining a match in progress while the host is performing a combat roll would play firing animation on the client for the host character, for the duration of the match
Fixed an issue so Vanguards who are charging as they die are no longer being routed to the ground
Fixed Host migration that would sometimes cause players to start on an incorrect wave
Fixed the issue when a client quitting a match during deep bleedout causes muted/ducked audio to persist into next match
Fixed the issue that when being revived at the same time as being executed would leave players in an T-Pose state
Fixed the issue that when a Banshee takes enough damage to stop her charge state, her normal state is not immediately returned
Fixed the issue where a player could enter a state when completing cover interactions near a ladder which could lead them to becoming invulnerable and unable to deal damage
Fixed game hitching of 1-2 seconds at start of waves
Fixed clients occasionally seeing nonstop firing visual effects
Fixed evaded projectiles having an erratic course
Fixed an issue where selecting resume after death could occasionally cause henchmen to not spawn properly
Fixed weapon recoil that could become reversed with a Turian when stability mod and passive power present
Fixed the cover slot in Meet the Diplomats mission would cause a player to become stuck
Fixed Geth prime and harvesters taking headshot bonus damage when they shouldn’t
Fixed shooting the atlas in the cockpit with a penetration weapon doing double damage
Fixed the Kishock Sniper Rifle that would hit head bone (critical hit) on enemies that should not be possible, such as the Brute, Banshee and Ravager
Fixed and issue where clients in cover cannot do any damage to targets at wide angles relative to the cover
Fixed an issue where player can glitch their melee combo to only perform cover lean melee animations
Fixed an issue where while dying in multiplayer, if the player pressed the prolong life button too quickly they could erroneously die
Fixed an issue so Drell Adept Reave audio plays at full volume for all players
Fixed an issue that an interrupt could sometimes fail to prevent a Cerberus engineer from building a turret
Fixed a crash in conversations after Investigate Sanctuary mission
Fixed an issue to prevent gear items from Rebellion DLC getting cleared between matches
Fixed an issue so ammo consumables, such as cyro ammo, would not replicated from host to clients
Fixed the Memory Leak going in and out of Multiplayer Menus
Added feature to remove AFK players after a set amount of inactivity
Added a cooldown to Ops Survial consumable
Made ammo consumables insta-reload and damage bonus
Xbox Only:

Fixed an issue where Mass Effect 3 soft locks in character screen if user unplugs Ethernet at “Checking downloadable content…” after accepting an invitation from multiplayer menu

That is a hell of a lot of bugs to fix. Lol.