I highly recommend spending a day or two in the park; however, it is a bit chilly this time of year. If you do stay, reserve a cabin in advance so that you can enjoy the scenery from a wood burning fireplace.
The leaves have already turned and most are probably on the ground, now. Shenandoah usually turns mid-October... slightly before the rest of the area. It's not really high elevation (3000' plus or minus), but the wildlife is impressive. Expect to see black bear, turkey, deer, hogs, eagles, hawks, and other little critters (rabbits, etc, etc). The snakes have probably packed up shop this time of year. Also, there are many waterfalls and trails right off Skyline Drive that are very dramatic.
If you want to fly some nestalgic aircraft, I recommend two places.
Blue Ridge Helicopters (click here), recommended by
FL, is located just minutes from the entrance to Skyline Drive. You've probably flown a B47G2 already, but at least you'll get to view the valley from the air before driving in the woodlands.
Since you'll be at Kitty Hawk, I recommend
East Carolina Helicopters (click here), located in Washington, North Carolina (not the District of Columbia). If you haven't flown a Brantly B2B before, it is a real experience you shouldn't miss out on. See
this thread (click here) for a review of the B2B.
Also, check your PM's.