With the introduction of GDrive by Google, a Virtual PC is very possible in the nearing future. Soon enough what we can do on a PC can be conducted over the Web. In order for this to happen, applications and plug-ins will need to be created to work with this GDrive technology. There were also rumor that Google is creating an OS to be run on the Web. If this is true, then I say: "We need to be ready for a Virtual PC pretty soon."
Read more on this at Playfuls.com.