Lol. I actually quoted your post by accident, but this thing is hilarious. He uses the abrogation of verses relating to alcohol to prove that sex with slaves is no longer allowed, when there was absolutely no abrogation for the verses relating to sex... and then he brings up international law banning slavery... well I guess international law abrogated the Quran.
Well, that's Zakir Naik for you.
But he doesn't circumvent the permitted slavery issue like Yusuf Estes.
"Does Islam allow slavery?
Absolutely, yes it does, Islam does. But wait, hold on, before you go any further, there's only one kind of slavery, and it's only one way. What am I talking about? I'm talking about Allah. Not that Allah is our slave, but we are all slaves to Allah. This is the meaning, of the slave, of Allah. Slave of Allah."
http://www.youtube.com/watch?v=_ubpDRRkDis