The DS demonstration was very interesting. The licensing is particularly intriguing–one copy of each application can be shared by up to 16 DS units! Very cost effective. The cost of a DS is very reasonable, too. I think the unit is also widely owned by so many students that schools could take advantage and not have to purchase as many. Can you imagine a student being told to bring their DS to school?
PSP offers some unique advantages in terms of storage, video playback, etc. I will have to do some digging to find schools utilizing the PSP.