Ambys,
I'm doing Denali this year too. I also have the D50. I opted out of taking it up the mountain though. The first couple of camps can be quite wet depending on the time of year you're planning on climbing. The last thing I wanted to do was to trash my digital SLR by getting water in it. So I went to my local camera shop and explained what I was doing and my concerns and they handed me the Nikon COOLPIX L12. It's wonderfully light, about 5oz with batteries. When loaded with fresh Lithium batteries can take about 500 shots. It excepts up to a 4GB card and has a host of brilliant built in features. The zoom isn't the best in the world but I'm willing to make that sacrifice whereas I'm not willing to sacrifice my D50.
Best of luck to you on your climb. I'm at 27 days now and counting.