Whatever your learner objectives, I would suggest "Less tell & more DO". Too many orientation programs are just too classroomy. I would also strongly suggest that you do follow-up evaluations 90 days afterward... to find out what was 'most helpful', 'least helpful' & 'what I wish I had been told'. This will help you keep on improving your program.
Customer Service role play (it's fun to be the gripey patient)
The Instrument Game - learner competition to identify pieces & parts from your common sterile trays
Get to know your partners- familiarization with first responders receiving departments (personnel, limitiations & strengths, etc.)
Shoot-outs: since rapid action is a highly desired characteristic of ED nurses, stage friendly competitions to see how fast learners can accurately perform various tasks while being coached by current staff members -- Cheesy prizes are always fun
Thanks to rbezemek I thought of a book that has helped me a lot "Telling ain't Training". It walks you through creating objectives, planning with fun in mind, planning for different types of learners --- and is an easy read. My daughter is not a nurse, but found the book useful for her business training as well. I got mine from Amazon.com