The Apple-authored driver appletmp.sys halts Windows 7 startup on Macbook Air Following a Windows Update which required a reboot, Windows 7 (64 bit) cannot launch successfully.  The Windows System Recovery tool has been unable to fix the problem with any of the recovery points I have tried.  The only system image available is from the same time as the Windows Update, so it seems pointless to try.

This thread on the Apple Discussions board has more details.

Any suggestions?
I wound up doing a fresh install of Windows 7 and leaving the trackpad off.  It probably makes sense to keep a USB mouse handy.