From my past experience in the Navy, I can easily see a place for both laser and rounds. One aspect I can see lasers doing is in a missile defence system. When an anti ship missile is speeding its way towards a ship, guns can shoot it down BUT the speed and relatively short range of the gun, allows that explosion to come a bit too close for comfort. Now a laser could strike further away and nullify that effect. With that in mind guns will have a place far into at least this century as they can still do what missiles and lasers can not do such as fire warning shots, shore bombarded and rapid close range strike. I also feel that the Navy brass may be a bit cautious about replacing guns outright looking at the Air Force's experience with gunless F-4s in Vietnam.