To add to your line of reasoning, the wedding is of short duration but there will be thousands of (famous people that your average viewer will recognize) people

To add to your line of reasoning, the wedding is of short duration but there will be thousands of (famous people that your average viewer will recognize) people to interview. The japan incident doesn't have that. It is a much slower event, it is all aftermath and ongoing work on the reactor. While the number of people effected is greater the number of officials, pundits, and famous(to their audience) people to interview on location is much smaller.