it has highlighting but to actually be productive would need:
autocompletion
quick way of looking at documentation.
way to execute commands (i.e. embed python).
It could be that idle would be useful but this is not compiled properly on the device; complains about python-tk package. Not sure if it is safe to just install from whatever dev repository it is in...
My main requirement is decent offline documentation. It would be a good project to gather together all relevant API docs and make them available as a single download, updated regularly.
Currently documentation is spread amongst Wikis, PDFs, various project-specific API docs, etc. and is often not in a format conducive for downloading. wget has been my friend..
Considering the screen realestate is so small, I would prefer switching from editor to browser (or other suitable doc reader) rather than having code-completion/pop-ups.