Will Virtual PC for mac v7 work with an new iMac

Basically, if your new iMac has the new Intel processor (or any Intel based processor Macs) your Virtual PC v7 will not work on it. It is designed for iMacs/Macs that are not Intel Based machines (that run on the Motorola processors like the G3, G4 lines, etc).
All Intel based iMacs/Macs are capable of running Windows using a Dual boot startup that is available at the Mac Store or online. Check the Apple website for instructions, they are always updating the software. :)