In all states that I know of that I have seen the law on this issue, Domestic Violence is a specific exemption to the marital privelege. Additionally, any crime in which the spouse may have been a victim is also generally exempted from the privelege.
I went to court Wednesday (my trial was postponed), but it was confirmed by the attorney prosecuting me that my wife does not have to testify against me, eventhough we werent married during the incident. And I know for sure that for other crimes that the priveledge is allowed, even if the spouse is a victim.

FYI, you CAN get a PBJ for a domestic violence. I saw various people getting them when I went to court...waiting for a postponement of my own case.