Is Santos vs Marinez a unification bout?

Daniel Santos has the WBA regular title and Santos has the WBC interim title. Does that make their fight a unification fight. None of the press releases address this.

Can an interim title and a regular title be unified?; probably not.

Not that I care about alphabet titles, but since THE Junior middleweight championship is vacant it is somewhat relevant.

Doubt it. In fact I bet the WBC makes him give up the interim bauble before this fight. They did it with Casamayor when he took the Katsidis fight.