I suspect some third party will make a replacement head (since it is attachable) with electronics. Shockwave lab does a lot of low cost led's for example. I would prefer a sound chip with unicron talking myself, but lights would be cool too I guess.
Still you can queue up some sound clips on an iPhone if there isn't a 3rd party electronics release, and it will almost be as good. I'm not going to let anything take away the shine of owning the planet killer Unicron
On the lookout for MISB Headmaster Highbrow, Takara or Hasbro. I'm sure I could make you a sweet deal!