RE: Go here ... http://www.freerepublic.com/focus/f-religion/3129967/posts
Based on the link and response to the question provided... here is how I see his view:
As a matter of civil law, he recognizes that such unions (note the quotes) may be a way for Catholics to recognize the reality of a secular society without supporting same sex marriage.
The same principle I guess, applies to divorce. The Catholic Church FROWNS upon it, but recognizes that in a secular society, it may be made legal. That by no means tells us that the church will endorse such unions.