Wouldn't disk, memory, network, cache and really anything that could trigger an interrupt also need to be fully deterministic? It seems to me this is really what the jitter dance is measuring to get randomness. It is only reading the cycle counter, all of the above would affect that slightly.
Memory, disk and cache could be deterministic in an emulator. Imagine an emulator for embedded software. Network doesn't come online until booting has reached a certain point and at that time some keys may have already been generated. It is not a showstopper (after all the jitter algorithm did make it in to the actual kernel) but there are cases in which problems would be conceivable.
