Hi Greg,
Camping on the summit is pretty special. You get to watch the sunset, and then in the morning, you will likely be joined by early risers, coming up from both sides to watch the sunrise.
If you're planning on a one-day assault from Whitney Portal to the summit.... it can be done, you either need to go ultra-light, or be in super shape. (I did it once with ultralight equipment -- about 20 lbs, went up the shorter Mountaineers Route, then down the Main Trail next morning.) Be sure to haul enough water up, too. I took 3 liters, drinking one between last water and the summit.
Acclimatization is a problem for many but if you live at the 5k elevation common to CO, AMS shouldn't be an issue.
Sure hope you give us a trip report. And a sunset / sunrise picture, too!!
