true... to go to the biltmore house and not go inside would be a tragedy.
and, blueridge parkway is nearly 500 miles long, can you drive the 1st 20-30 miles and see everything worthwhile?
now come on

of course you cant see everything worthwhile in 30 miles. if that was the case it wouldnt be 500 miles long.

of course nobody is suggesting you drive the entire thing at one time. as you would imagine, not all parts are equally impressive, but still worth seeing eventually. the parts in the very northern nc and southern virginia are somewhat forgettable as are some of the parts right around asheville, since asheville sits in a valley and its elevation is only slightly over 2,000 ft as opposed to blowing rock which sits closer to 4,000 ft.
the best parts....
southern tip near great smokies to pisgah - that whole area of the NC mountains is amazing, not just on the BRP. highlands and cashiers are the home to tons of awesome waterfalls. this section also has the highest point on the BRP at 6,000ft. close by you have sapphire valley, pisgah, great smokies, nantahala river gorge, french broad river gorge.
http://www.blueridgeparkway.org/map5.htm using this map, if you are in the asheville area and only have time for a few hours i would go south on the BRP towards the great smokies, but it doesnt really get good until you get about 20-30 miles south of asheville (see part about asheville sitting in a valley)
to the north of asheville you have mt mitchell, the highest point east of the mississippi at 6,600 ft. but the peak itself doesnt really stand out as it blends in with the many mountains in the area over 6,000 ft. to be honest, i havent been on this section in a long time. highway 221 from marion to linville is a much cooler drive and it goes right by linville caverns.
my fav part of the BRP is from linville falls to slightly north of blowing rock, mainly because thats where i went to college, as did many others on this board. anyone from appalachian state can tell you about every square inch of the parkway in that area. sights include linville falls, grandfather mountain (much cooler to see than mt mitchell), the viaduct, rough ridge, thunder hill, price park and of course my personal fav... hebron rock colony.
http://www.blueridgeparkway.org/map4.htmanother really nice part of the parkway is way up in virginia in the skyline drive through shenadoah
http://www.blueridgeparkway.org/map1.htmyou've touched upon one of my fav subjects here flash, seeing as how i was a geography major from nc, through app state in the nc mountains, with a specialization in physical geography (mountain building, erosion, geology, rivers, watersheds etc....)... so yeah, dont get me started unless you want to be bored out of your mind.