The league doesn't set start times, the teams do. The national networks can set the start times for the games they cover. Last year, the Wings were going to switch to a 7pm start time. Then they got the Versus schedule and they wanted all their games to start at 7:30 and were carrying like a dozen Wings home games. Holland thought it would be too confusing to have so many games with a different start time, so he decided to keep it at 7:30. I was hoping the change to the Eastern Conference would prompt the Wings to change to 7pm, but no dice yet.
Yea that's basically what I said lol. The Wings being on the edge of the timezone, have always wanted their games at 7:30. That and the fact JLA usually has a sizable late arriving crowd in recent history, has probably prompted them to keep the start times at 7:30.