The St. Louis Blues have been playing in the Scottrade Center (under various names) since 1994. There have been tweaks over the years, but nothing like the arena will see this summer.
Some of the past changes include taking out seats for the current Pepsi Plaza. There was the addition of a video ribbon and there have been a couple different versions of the scoreboard/videoboard.
However, there has never been the kind of undertaking the Blues and team/building owner Tom Stillman are undertaking right now. They are all but going to overhaul the entire arena, with new seating, a new ice surface and cooling system and more.