Hi - I'm putting a new gaming rig together, planning to install windows 8.1 64-bit. Will I be able to transfer and use the save games generated on my current machine running Windows 7 32-bit? Any general thoughts on this process of moving from an old machine to a new, w.r.t New Vegas (pitfalls, etc.)? Many thanks!

Just copy your saves games onto a flash drive, or other storage medium, and transfer them over to the new rig afterwards. You can find them in Documents/My Games/FalloutNV. They're exactly the same format regardless of what OS you're using.

Excellent, thank you, I just assumed it couldn't be that straightforward. Shame Bethesda support couldn't tell me that...

They probably didn't think of it because it is so straight forward.