Sketchup 2013 was just recently announced! I put together a post that has everything you need to know about Sketchup 2013. It has information on all the new upgrades, pricing, and also takes a look at the new license agreement. Something you'll want to take a look at if you currently use the free version of Sketchup for commercial work.
Trimble changed the name of the free version to be officially called "Sketchup Make". This is to avoid confusion with Sketchup Pro. (How many times have you had to explain to someone that Sketchup is a fully featured program, not just a trial of Sketchup Pro?) This should make it sound more like a complete program.
Many new features in Sketchup Pro (specifically Layout). Also, they introduced the "Extensions warehouse". Get all your plugins in one place. Find out all about it at http://www.mastersketchup.com/sketchup2013/