Late night host Jimmy Kimmel is taking another short break from ? Jimmy Kimmel Live!? to be with his son, William John, who just underwent his second heart surgery. ABC confirmed in a statement that ' Jimmy Kimmel Live!' will feature guest hosts this week, including Chris Pratt, Tracee Ellis Ross, Neil Patrick Harris and Melissa McCarthy. The seven-month-old's heart surgery was planned for October, but it was postponed. In May, the late night host revealed that his son was born with heart defects.