Microsoft's vexing dumping of vdproj install projects in VS 2012 leads one to try Installshield LE which is sort of built into VS2012. Sadly, it creates installers that do not work in any way shape or form with 64 bit.
So for instance clicking the Office 2010 installed checkbox only makes a prerequisite for 32 bit Office. It fails to detect 64 bit.
After a lot of chickenless head exploration of Installshield the bottom line is: 1) You need the Professional or Premiere version in order to deal with 64 bit. 2) You need to edit their provided condition to make a compound one that ORs all the guids of Office that you are interested in together as it only checks for one of the many out of the box. This details the structure of the GUIDS: http://support.microsoft.com/kb/2186281?wa=wsignin1.0. I found it helpful to install various versions in a VM and then using regedit to see what the GUID ends up being.
This post is so that someone can actually discover this with a Google search, instead of it being hidden behind a paywall / private support site.
Apparently the small print referenced here should have been one clue: Does InstallShield Limited Edition Support 64 bit Installer?
The current Office prerequisite in Installshield is also misleadingly worded. It should really be "Office 2010 Home & Professional 32 bit".
Perhaps they intend to upgrade it over time to be comprehensive or perhaps everyone has to go through the same hassle to fix it for a few cases they care about. The support guy claimed there are too many GUIDS for all the combinations of versions, bitness, releases etc.
Home & Student, Home & Professional, Professional, Office 2010 Professional Plus License 32bit, 64bit, Languages mangled in there, Service Packs, etc. Depending on the set you care about the number of GUIDS is rather large.