Is it poosible that virtual applience consists of 2 parts:
\- virtual applience by tself;
\- host OS installtion/configuration script.
There are some ideas (for example Multi PC (one PC emulates 2 or more PCs with extra i/o pysical devices)), but this require host OS configuaration (like VM-to-monitor binding, input devices-to-VM binding etc.).
Also there are some more ideas for virtual appliences, but almost each require additional software for host OS.