This is a really interesting list Christine - not least because it highlights some of the really important features needed for consistent classroom use.
A few comments that I'd be interested to develop within this forum:
4.A keyboard solution that works for the flexibility of not being at a desk or hard surface. (students frequently use a handheld in their lap)
There are many input devices for PDAs - from data sensors and image catpure to keyboards and styluses. Considering an affordance of handhelds is that they allow mobility (which includes working on your lap) - is the keyboard necessary? I ask as, although I use an attachable keyboard for my PDA, younger users (who aren't used to keyboard writing) may prefer other input methods.
11.Easy solutions for getting student work into the hands of the teacher from a variety of apps. Hotsyncing is cumbersome for a teacher to access multiple student files. (See PAAM by GoKnow Software)
A really important point - and I think one that can be developed to incorporate sharing work with other students, groups and agencies outside of school as appropriate. Giving the learner control over access of their work and easy opportunity to share and work collaboratively is really important. Interesting to think about the best way to work collaboratively with PDAs (for instance bluechat & blueboard on the Palm) - what software/connectivity issues this raises.
A great list that I hope we can add to through this forum.
Incidentally, I looked at some of the lesson plans on your site (hyperlink in "introduce yourself") - you are working with some really exciting teachers!