I don't think so - not yet!
Viruses are only possible with objects that are executable. Anything that is passively viewed is safe - this is why emails were always safe until Microsoft started adding ActiveX components etc, which meant they were no longer passive.
Current video and audio is purely passive - the computer receives a stream of data - does a bit of decoding - then chucks it to the speakers.
Of course there is the move to make it more interactive (real player allows some interaction).. and the more that is added the more risk of viruses.