Most mash-ups seldom make sense, but they almost always end up being even better and more entertaining than the originals. Thus a Pac-Man and Star Wars mash-up seems rather odd until one sees the end product.
Pac Wars, the Star Wars and Pac-Man inspired mash-up, was designed by Theduc for NeatoShop, an online store that sells unique geek merchandise that has been featured on Neatorama.
Pac Wars reminds me a lot of Angry Birds Star Wars and is a game mash-up that I think Namco should seriously consider. I, for one, would by a Pac Wars video game. Until then, however, I guess I may just have to spring for the Pac Wars t-shirt.