I own a 1/2 undivided interest in a piece of land.  The other 1/2 owner, Mr. X plans to buy a seperate piece of land that I would rather have.  Now, would there be any problems with me executing a 1031 exchange giving Mr. X my 1/2 interest for the new property he has just bought.  In the end, I will own the new property and the Mr. X would own the entirety of the original property.  Just wondering if there were any implications, i.e. disguised sale problems

No, this would be fine.  This is a classic "two party swap" where you both draft deeds with you deeding him your 1/2 interest in the exisiting property and he deeding you the entire new property.   You would arrange to have both deeds recorded simultaneously so that it is a concurrrent 1031 tax deferred exchange (this is important).  I'm assuming that the property values are the same, but if there is a difference you can agree to value them the same or you can have one party pay the other party the difference would could be set-up as a 1031 exchange with a Qualified Intermediary and used to acquire a second property or could be treated as boot and taxed. 

1031 Exchange Resources