On my last trip, this was one of the few places where a chunk of the wall still stood. On my first trip, the checkpoint still existed itself, but I believe was gone by second visit a year later.
As for the museum itself, it's an eerie mix of history, art, and philosophy. There are the necessary explorations as to what the Wall was and what it signified. There are propaganda posters left from the days of the Wall, as well as pictures of the graffiti and art that had been put on the Wall over the years.
One room specializes in the attempts -- both successful and failed -- to get over the Wall. In this section, there are fake car trunks, makeshift hang-gliders, and altered luggage that could bring to mind the likes of James Bond.