I share you pain friends..
According to Adrynalyne, someone (VZW or Samsung) has disabled the stock android voice dialing feature to trigger via bluetooth.
There are no other options apart from Nuance, or Vlingo, for right now. Hopefully the dev's will figure this out and be able to dial into it and get it back.
I use Nuance and have pretty good results.
This was one of the main features I was looking forward to with Froyo and was sorely disappointed when there wasn't a fix. There isn't currently a custom Rom that I know of, that incorporates the stock android bluetooth Voice Dialing, etc for the Fascinate.
Hope that helps!