Not sure about the way in which the version changer works, I think it's classed as bad useability if a radio button does something without you using a submit button.
The BBC websites seem to be undergoing a rather large amount of tweaking at the moment. There are loads of them moving over to CSS based designs, many of the aging backend apps are being replaced (h2 being replaced with dna message boards, the voting system...) and they are generally becomming more broadbandish and webby with links out to other websites and Nick Robinsons new blog.
Nice to see some cost cutting being made by using better, more efficent stuff than just sacking everyone and shutting down websites (*cough* Cult)