The first major update to vbMAPI now adds full 64 bit support when running under Office 2010 64 bit edition.
vbMAPI - Version History (scroll down to the bottom)
Whilst this might not sound like a big deal, this means two things:
#1) a 64-bit version of the developer add-in is available (as far as I'm aware, this is the first VBA7 64 bit add-in available). Both versions are installed automatically.
#2) and the native machine code stuff (Virtual-COM) now contains both x86 and x64 binaries and automatically switches between them. This means that you don't have to distribute anything differently (i.e. independence of the bitness of the Office version installed).
A lot of work went into supporting 64 bit, and this now paves the way for updating some of our other products similarly. Keep an eye out for the updates :)