Several threads on this. Just do a search for more info.
But, any year JK soft top will work on any other year JK, as long as all the hardware from the top are included. For instance, the top from a 2008 will not work with door surrounds from a 2011. So just make sure all the parts are included with the top you purchase and you should be good to go.
In 2010, Jeep started using a cable system over the door surrounds vs the clip system they had used in prior years. This is supposed to help with some leaking issues the prior years had, though the new ones can leak as well, of course. The windows in the 2011+ tops also are a little larger than previous years.
In other words, what ^he said. lol