As Jon slept, he had no idea that his wish did do something and something that would indeed be considered interesting, though only he would notice it, as he was the only one to hear his own wish. When he finally woke up the next morning, he might notice changes, or not, as they'd be subtle at first, but Jon and his entire family (his dad James, his mom Linda, his 15-year old Goth sister Zoe, and his 10-year old brother Mikey) would be in the process of changing, over the next few days. But Jon's family wasn't the only one. Four other families would be changing as well. And they would all be changing to become like the McMillan family (Richard, his wife Susan, and their daughter - the one and only Sarah McMillan herself).
The members of each family wouldn't become copies of the McMillans, though. Instead, they would eventually have the same basic personalities and lifestyles as the McMillans, while physically (mostly) staying themselves. In the end, the father of the family would be like Richard - handsome, charismatic, and rich, due to a high-paying job; the mother of the family would be like Susan - vain, shallow, a socialite with a job that solely exploits her beauty (essentially a trophy wife); and the child or children of the family would be like Sarah - sexy, manipulative bitch.
Now for the families who will become more and more like them over the next few days, with reality changing along with them - the Gibson family, as already stated, the Ferguson family (father Roger, mother Laura, daughter Nadine), the Meadows family (father Gary, mother Loraine, sons Biff and Wesley), the Black family (father Benjamin, mother Bethany, daughter Karyn), and lastly the Meshida family (father Katashi, mother Kamiko, daughter Yukio).