* Arma 2: British Armed Forces Lite - all units, vehicles and weapons from Arma 2: British Armed Forces are included in this patch with lower quality textures and audio files. The full version of Arma 2: British Armed Forces with high resolution textures and packed with a new campaign and large selection of new single player missions is available for purchase, see http://www.arma2.com/baf for more information about the content of Arma 2: British Armed Forces.

* Numerous stability and functionality fixes and improvements.

* Reworked MP Session Browser and Mission Selector.

* Engineer - Engineers have undergone some serious training and are now capable of repairing damaged vehicles and defusing mines. An engineer can patch up a badly damaged vehicle, making it operable. A damaged component can be repaired to 60% status; however, note that the total damage inflicted upon the vehicle persists, and further damage will be calculated cumulatively. An engineer can defuse mines, satchels, and IEDs. It's possible to order an engineer to repair/defuse something by standing close to it, selecting 'engineer' in your command bar, and then pressing '6-1' ('action' > 'defuse'/'repair'). If you are engineer yourself, simply select 'action' > 'defuse'/'repair' from the Action Menu (default binding is the middle mouse button).

* Artillery Computer - All indirect fire weapons can exploit the brand new artillery computer by selecting it in the Action Menu (default binding is the mouse wheel). The artillery computer initiates an interface where you can see your weapon, and the associated minimal and maximal ranges on the map. You may adjust your fire mode in the menu to the right and select the target area that your ordinance will strike. The display will indicate an estimated time to target; once you fire the ordinance - by clicking the 'Fire' button - the interface will track each shot. Your aim will change according to your actions once you leave the artillery computer.[/i]

Edit1 : Maruk has published new informations us on the BI Forums :

* Patch 1.54 is not compatible with the Steam version, Steam users have to wait for Steam auto-update

* A2: BAF DLC available to purchase through stores linked from http://www.arma2.com/baf , does not contain the patch 1.54 and users need to update their game to 1.54 before they can run A2BAF Full Version.

* BAF Lite included in the patch is scaled down quality of units and audio and does not contain any single player scenarios, BAF Lite is available primerily for Dedicated Servers and Clients in multiplayer to allow seamless online operation of A2OA + BAF

* Some users report problem updating Mission_E.pbo. We are looking into this issue and we will provide fix for them once we know what the problem was plus will probably provide download link for most recent missions_e.pbo

Edit2 : Jennik adds : [i]In case you experience an "Error found in file EXPANSIONS\ADDONS\missions_e.pbo" error during the update installation, click the "Ignore" button and continue with installation.
When finished, download the file missions_e.pbo separately here, then search and replace the original file within your Arma 2 installation folder.