Hello,
I’m trying to resume every changes made through the years 2010-2013 of the x5m before the F85 model comes out. I’ll list what I’ve been able to find. Feel free to contribute.

North America Production numbers from X5 M production #'s
2009 - 4
2010 - 1063
2011 - 1109
2012 - 869
2013 - 1084

2010
http://www.xoutpost.com/bmw-sav-forums/x-m-forum/60127-official-x5-m-press-release-pics-updated-post-51-a.html

As of 7/09 production
First model year if we discard the 4 vehicles made in 2009.

2011
http://www.xoutpost.com/bmw-sav-forums/x-m-forum/69898-2011-arrives-early-bmw-my2011.html
http://www.xoutpost.com/bmw-sav-forums/x-m-forum/70361-spring-2010-changes-m-lineup-incl-changes-x5-m-x6-m.html

As of 4/10 production:
Both models
• Brake Energy Regeneration
• Dynamic Led Brake lights
• Side-view cameras available as stand-alone option
• Speed limit info for various markets
• Premium Sound Package replaces DVD changer with Satellite Radio
• Extensive revision of options/ availability strategy (ex: floor mats, velours)
• Three features become Priority 1 options:

• Head-up Display,
  Rear Seat Entertainment and
  iPod/USB Adapter

X5 M only
• New “glowing bars” LED taillights
• Opening angle of rear doors increased for easier entry and egress

As of 9/10 production:
Both models
• iPod/USB Adapter with refinements and new functionality:
• No longer includes Y-cable; iPod connects directly to vehicle audio system via USB port
• Album cover can be seen in iDrive display if contained in song’s metadata
• Voice Command (included with standard Navigation system) can be used to control external devices and select their program material
• Bluetooth adds functionality:
• Mobile-office integration of BlackBerry smartphone gives access to e-mail, text messages and notes through iDrive system
• Re-dial and received-calls lists download each time mobile device is connected and after each call
• Bluetooth music streaming from mobile device, controllable through iDrive

2012
http://www.xoutpost.com/bmw-sav-forums/x-m-forum/79177-march-2011-changes-x5-m-x6-m.html

As of 4/11 production:
Both models
• iPod/USB Adapter added as standard equipment
• BMW Apps newly available
• In Premium Sound Package, former iPod/USB Adapter is deleted and BMW Apps is required
• Priority 1 options 1 revised;
now Head-up Display, Satellite Radio
X5 only
• Power liftgate added as standard equipment
X6 only
• 5-seater option newly available

2013
http://www.xoutpost.com/bmw-sav-forums/x-m-forum/85732-official-pics-facelift-2013-x5-m-x6-m.html

As of 4/12 production:
Both models
• Optional Full LED headlights
• Blue-painted brake calipers
• Both wheel designs now available on both models (formerly each design was exclusive to one model)
• Standard Multi-Contour front seats
• Optional Full Merino leather interior: Mugello Red replaces Sakir Orange as one of five available color schemes
X6 M only
• Revised front end with wider grille + newly sculpted slats
• Aluminum hood with prominent “power dome”
• Newly designed LED taillights

Individual options available
http://www.xoutpost.com/bmw-sav-forums/x-m-forum/68863-individual-x5-m-x6-m.html

Sources:
BMW M Registry - FAQ E70 X5 M
Fast Facts from BMW University from 2010 to 2013