- Rechargeable wireless Mighty Mouse with a Scroll Ball that does not suck!!!
- Mail.app with builtin GPG and S/MIME support (also on iPhone)
- Ability to forward text messages on iPhone
- Different signatures for each mail account on iPhone
- Installer and/or Cydia in AppStore :-)
Looks like someone had the same idea: TechCrunch: Please Fix The iPhone: A To-Do List for Steve Jobs.