Sadly, even with the most recent update (0.31), it still takes around the same amount of memory (5.31 GB in this instance) and may have actually increased with the graphic tweaks. I hope they see this and find some way to reduce memory use on start up (and also allow the opening of a graphics menu from start as well).
edit: on playing, and on the lowest setting, it uses even more, using around 6.2 - 5.9 GB of memory.