Qemu can run vista on a ps3 through Linux but can Qemu be altered to run Vita on a PS3 without using Linux? Since Linux is ultimately just an operating system isn't the application that is really the bridge between the ps3 and Vista?
qemu is a processor emulator. Vista runs on x86 architecture which PS3 does not have, so you need Qemu. As you say it is an application, and as such, it needs an operating system, just like any other app.