Christmas 2007's tree stayed up until almost Christmas 2008. The only reason it went away was because I gave it to RainhaDoTexugo as we were packing up to move to Texas.
Our friends & neighbors loved it! We eventually took off the the truly Christmas-y ornaments and left up most of the Star Wars & Star Trek stuff. Then those came down and it was our "Whatever the Latest Holiday Is" Tree. It was an Easter Tree, an Arbor Day Tree, a Memorial Tree, a Labor Tree, a 4th of July Tree, a Haloween Tree, a President's Day Tree, and an Unbirthday Tree.
Since we travelled for Christmas 2009, we didn't replace it. But since we'll be in town for Christmas 2010, we'll need to get a new one.