I think both the NFL and the NBA need to study just how the 2004-2005 season lockout effect set back the NHL for a long time. Remember, before that lockout, the NHL was a regular fixture on ESPN; that lockout resulted in the NHL being forced to a contract on Versus network on weekday nights and NBC on weekends. A combination NFL/NBA lockout in the fall of 2011 could end up with a complete scrambling of TV contracts starting the fall of 2012.
A lot of that was the NHL's fault. They insisted on getting paid for broadcast rights, and ESPN decided it wasn't worth the cost. If they had just given away broadcast rights to ESPN, or even paid them to broadcast the games, the returns they would have gotten due to increased exposure would have more than paid for any lost revenue.
Once upon a time, ESPN and ESPN2 were regularly doing 4-5 NHL games a week, and showing doubleheaders (and sometimes even more, between the two stations) during the playoffs.