The current patch contains the following changes:

MULTIPLAYER

* Added a new Steam Lobby feature to the Multiplayer section as an alternative to the existing server search. A lobby is a place for players to gather before joining or creating a server. The most important feature of a Lobby is that it allows one to join servers running on a non-public IP, bypassing network address translation. It will of course also allow you to send players to a public IP server just as well. When a lobby links to a public IP server, that server can be accessed both from the Lobby, or directly from the Server search. With a non-public IP, the only way to access a server is through a lobby. When running a dedicated server, the lobby host can link to it by pressing the Find Server button. Otherwise just press Play to create a new Server.
* Fixed certain aircraft flame and smoke effects not syncing when playing on-line and recording tracks.

GRAPHICS

* Made massive improvements to framerate in regards to the terrain engine. This will be most noticeable on machines with 4+ CPU cores.
* Made SSAO optional. It can be toggled on the fly with a checkbox in Video Options. Turning SSAO off will slightly decrease the graphical quality of the game while improving performance.
* Texture quality slider added to video options. The settings are Original (no change), High (reduced 2x), Medium (reduced 4x) and Low (reduced 8x). Lowering texture size will cause significant performance gain on lower-end machines at the expense of the graphic quality. Please not that the feature is smart enough not to downscale aircraft textures, so the most crucial components of the game will remain unaffected.
* Made sure that grass no longer grows through runways or roads.
* Re-enabled anti-aliasing on DirectX 9.

AIRCRAFT

* Completely removed overload assessment from carburetters. Rolls-Royce engines will now cut if overload is negative, and will not cut if it is positive. (old values were sneezing at .5G, and cut-out at .25 which we felt were dead on, but this apparently confused most of the players)
* When starting in mid-air, all gyro instruments will be spinned up so you don't have to wait for AH to get in shape, as well as course setters and DI set to actual heading for you.
* Reworked damage module to work dramatically faster when a plane is under heavy bullet bombardment.
* Elevator trim is now set close to neutral when starting in air.
* Returned the water splash when a plane plummets into the water.
* The Spitfire DM will no longer occasionally ignore detached rear fuselage.
* Changed WEP control feedback on Bf. 109. Rather than showing an 'On-Off' message, it now will show if it actually is switched on, and when it actually switches off.
* Fixed minor Bf. 109 damage visuals.
* Ju. 88 gear struts now break off gear well covers when they detach from the plane.
* Fixed missing power cords in Bf. 109 and Hurricane cockpits.
* Fixed visual issue with bullet holes in cockpit glass.
* Fixed issue with FW. 200 radiator flaps floating on detached engines.
* Fixed missing geometry on Spitfire's damaged right wing under the landing flap.
* Reworked movement of the Hurricane boost cut-out pull knob.
* Fixed minor Bf. 110 damage visuals.
* Propellers on detached motors will now appear stalled.
* An invisible mental force won't raise your landing flaps on the strip after you start the engine any more.
* Replaced every tachometer in every British and Italian plane with an electrical type, since some people find needle movement on the mechanical type not what they expected.
* Jammed and stuck motors won't budge when flying at high speed.
* Adjusted behavior of broken engines.
* Doubled quantity of air in Bf. 109 undercarriage emergency discharge containers. This makes it more likely that your emergency gear will have enough momentum to push the struts down till they lock.
* Landing flaps on Bf. 110 can now be ripped off only as whole, not in halves.
* Bf. 110 hydraulics pump is now driven by its right motor as it should.
* Fixed a bug with carburetor backfire always causing intake damage.
* New assessment causes less initial destruction to surrounding area when fuel storage explodes.
* New spectacular fuel storage explosions (blow up those large round cistern buildings around the map)
* Flames and heat from aerial fires will now make a plane catch fire, rather than break its parts.
* Fuel storage fires, on the contrary, will be more destructive.
* Implemented new getParameter() to AiAircraft interface to allow more access to aircraft state in mission scripts.

MISC

* Added four new benchmark tracks. The Black Death is the new version of the most famous track from Il-2. It will tax your system to the absolute limit.