The answer is YES and NO...
The whole theory behind the structure of Gigasampler is that it is built upon the intricate parts of windows....(per tascam) and even though Virtual PC emulates those parts of the Windows architecture, It is just that an Emulation.
We have tested Gigasampler here on a G4/867mhz with 384mg/ram with Virtual PC 4.0 on MAC OS 9.2.2...
The program installed with no problems and was able to launch after a few little hiccups - (the registration process is a little buggy)
we loaded up a few of the smaller sounds and they seem to play O.K. but the latency is not even close to the standard that Gigasampler is known for.
So can you use it on a "get you by" basis - as far as to play and audtion sounds.. sure you can
But as far as the creative process goes, Virtual PC is just not strong enough to power the demands of a program like Giga.