I'd assume that those applications (Carrara, Vue, PSP and Hexagon) will all run under XP Pro 64, but won't all benefit from the 64-bit environment.   The ones that are designed to run 32-bit should continue to do so.   Vue 6 will definitely exploit 64 bits.   It's why you can never have too much memory to run Vue.   I don't think Carrara can use 64-bit yet, though, and I don't imagine Hexagon can, or PSP.   I can't think that there is any feature of PSP that needs a particularly large amount of memory, so I'd expect that to be 32-bit (I don't use it, though, so I'm guessing).