Sound and video would be directly supported by the datatype. So if you have a datatype that supports streaming it would stream, in practice there are few that do so (if any?) so the final answer is probably no, not at the moment, but it's not a limit of MultiViewer but rather of the underlying datatype.
The MP3 datatype supports streaming. Unfortunately this makes it entirely useless for using as a loader, as the two are mutually exclusive.
All the animation datatypes stream - it's basically enforced for those.
