It is not an issue of "regulation" by an outward effort but about self confession and the spiritual, psychological state in self revelation by those in the Priesthood.
While, yes, standards are being revised for admission to Seminaries, any applicant who would conceal a homosexual identity in the admissions and even later enrollment process (if that happened), would be by that process already admitting a problematic pscyhology in that act of concealment alone.
The standards are there and have been but have been abused and ignored and manipulated to include homosexuals (and homosexual activity) in the Priesthood in defiance of the Catholic Church and scriptural definition of what homosexuality is. I think that Pope Benedict has just righted the terrible confusion that was allowed under Pope John Paul, bless him -- but in this important area, he did not lead.
Another excellent point!