Nuance acquired the distribution rights of ViaVoice a few years ago, therefore; their haven’t been any new releases of VoiceVoice in a couple of years. The attached comparison matrix will show a few differences between Dragon NaturallySpeaking v8 & VoiceVoice v10.
http://www.zazaknowledge.com/resources//13756/Nuance/Comparison Matrices/Dragon NaturallySpeaking v8 vs. Via Voice v10.pdf
Verification Source: Nuance Partner Portal