Taurus had a prototype of a Raging Bull in .223 at, IIRC, the 2006 Shot Show. Unfortunately there has been no follow-up word from Taurus in regards to these so it appears they've either scrapped the plans or pushed back the release date. No word however makes me think it's the former reason rather than the latter.
That really is too bad since there are some here, myself included, who would like to have one.