Just a quick note: Both of these films are in Blu-ray format. The reason that Play.com don't mention Region encoding is that they don't need to. There are only two Blu-ray regions. This copy of Tron/Tron:Legacy will work on all PS3s/Blu-ray player in Europe or America.
And on another note: This is an excellent set. The original TRON completely captivated me when I was a kid and still does to this day. It was an excellent example of what could be done with the technology of the day, and the sequel is no different. On its own, it's not the *best* film in the world, but you don't take that to heart. Playing both together you can see the vast evolution of 3D technology from the two times, and it displays itself perfectly when you consider the natural evolution of technology actually within the canon of TRON. The story in Legacy is reasonably weak, but I didn't even notice [mainly because of Qorra] but it is definitely worth a watch (after having seen the original).
Brilliant deal and one of the most influential sci-fi/nerd films of the late century. Worth a watch.