How do I know what version the Mini DisplayPort port is on my 2010 MacBook Pro?
The 2011 MBP (MacBookPro8,1) has thunderbolt, so either your machine is not a 2011, or it has thunderbolt. the 2010 MacBook Pros have MDP that supports audio as well as video (I have a 2009 which only does video).

Keep in mind that MDP and Thunderbolt look identical.