Originally posted by Lord Stark
It is quite possible the Emperor will be engaged in the netherworld of the Dark Side. Marr thinks Vitiate cannot be defeated by normal means, so I don't think it'll be a simple lets kill him. It'll likely be kinda like the gree mission where you go into the digital world.
I'd assume that The Emperor would entertain manifesting himself in a physical body, in all honesty. Though admittedly, there is plenty of room for speculation on what Bioware will ultimately do with Viti.