The last stable version of Blender was released on September 16, 2009. We've come a long way in the last one and a half years. Through three alpha releases and four betas (five if you count the 2.56 re-release). It's been a long road. One with many changes, hundreds of bugs fixed, lots of features added (and quite a few that weren't quite ready), and most of all: a lot of hard work. Someone posted a link to a very neat pdf document on the Blender website, from the very beginnings of the 2.5x project, describing the evolution of the Blender UI.
From all that, we got Blender 2.57.
It's always nice to see a few screenshots so I thought I'd go through an old project I'd done (Oceanscape) in 2.49 and see what it looked like in 2.57. It opened up fine, although I did have to readjust the layout a little, since the properties windows does not deal that well in horizontal view.