The list of new commands and system variables in AutoCAD 2010 can be found on:
 
www.cadforum.cz/commands
www.cadforum.cz/variables
 
or specifically (2010 only):
 
http://www.cadforum.cz/cadforum_en/command.asp?ver=2010
http://www.cadforum.cz/cadforum_en/variable.asp?ver=2010
 
(the LT limitations of A2010 may not be accurate yet)