Yes, Bro. Curtis, I believe that the prohibitions as to those particular sexual sins found in Leviticus 20 are still in effect today.
As I have stated here before, in the Old Testament you can find civil law, ceremonial law, and moral law.
Civil law does not apply to christians today. But, for example, if a christians chooses not to eat pork or shellfish, that is his or her business. But they should not impose that on any other christian.
Ceremonial law does not apply to christians today. Jesus was the final sacrfice and we are not to shed any more animal blood on an altar.
But the moral law, that which outlines God's plan for His people's moral nature, still applies....in my thinking.
Murder is still a sin. We don't stone people anymore, but it's still a sin.
Adultery/fornication is still a sin. Lying is still a sin. Idolatry is still a sin.
The passage you are referring to begins speaking of adultery in verse 10 and continues with other sexually immoral behavior. Jesus says that He fulfilled the law and he made us aware that even thinking about sexually deviant behavior is a sin.
So, yes, for my thinking........the sexual deviancy found in Leviticus 20 is still forbidden today. And even though Leviticus 20 does not mention internet pornography and the Playboy channel or The Sopranos or Sex in the City, I believe that the spirit of the law carries over to all of our modern immoralities. I do not believe that we are to stone people for it, because Jesus can forgive people and people can be saved from immoral lifestyles.
But would you not agree that far worse than stoning are the effects of diseases and other social/physical consequences paid by people who practice these lifestyles.