I haven't seen the "Family Guy" episode that's all over the news today; I did watch the clip the LA Times is hosting, which features the "getting ready for the date" musical number. As near as I can tell, the episode is about one of the Family Guy's kids going on a date with a girl who has Down Syndrome. There have been objections to it (from the Palin family FWIW) and the creator's response is that the show's humor has always been based on "biting satire" and that it's an "equal opportunity offender."
What about dating someone - or being someone - with Down Syndrome is a vice, folly, abuse or shortcoming that needs to be held up to censure? Unless one is speaking of someone bent on exploitation and concealing it as romantic intent. The musical number seemed to imply that the young man was genuinely fond of his date.
Good satire can make people uncomfortable, but not everything that makes people uncomfortable is satire. Sometimes, it's just hateful or mean. I'm not willing to categorically state which this show is - I haven't seen it - but I admit I have my suspicions.