Digital Foundry's Richard Leadbetter's put the "rumours" to rest regarding the differences between the PS3 and 360 versions of Ghostbusters. The PS3 version's resolution is far smaller, basically.
Rich tells us the PS3 version runs at 960x540, while the 360 game hits 1280x720.
And that's that.
Update: A Terminal Reality spokesperson told Joystiq yesterday: "For the record, the PS3 version [of Ghostbusters] is softer due to the 'quincunx' antialiasing filter and the fact we render at about 75% the resolution of the 360 version. So you cannot directly compare a screen shot of one to the other unless you scale them properly. The PS3 does have less available RAM than the 360 – but we managed to squeeze 3 out of 4 textures as full size on the PS3."