Well, from what i've heard about them, they definitely have some advantages.
For one, you can just move over the clips already saved on your hard drive to your computer. You don't have to worry about capturing and tapes, and all that jazz.
But, they are going to be geared very much towards consumers so you're probably not going to get the controls and flexibility like you will get with a miniDV camera. Also, i'm not sure how well an HDD camera would hold up skiing. It seems like all the bumps and vibrations (if you're follow camming) could really mess up the hard drive.
I'd say probably stick with the tapes...