If you stay on route I see no need to haul a big heavy rope up there. There are no bolts on the regular MR route except a few in the final staircase chute above the notch. I have never actually seen them but they are on the left side, east side, when going up. Supposedly they are there for winter ascents.
Realistically, there are only a few places your friends would feel they needed to be roped in. There is no place steep enough to rapel down, unless you are off in the cliffs. There are options also to climb here or there, looking for an easier way.
Take a look at the extensive list of pictures of the route.
http://www.mt-whitney.info/viewtopic.php?t=126If you want to take a short 50 foot piece of a not to heavy rope along, just in case, it is not a bad idea.