This is an old question in one form or another and as hospitals seek to make their ED's leaner, I think we'll see more paramedics in the ED and probably all over the hospital.
I bow to MedicRN's response. If you have VT, trauma etc or someother problem that has been covered in the paramedic "cookbook", you cannot beat them, however their training DOES not prepare them to do discharge teaching, to advocate for a client who ought not be dismissed, or to deal with problems that I call "complex nursing problems." In my career as an ED nurse I have refused to dismiss a woman from the ED with abdominal pain that the ED doc (new to the ED) had failed to do a pelvic on or tested for pregancy. I received a patient from experienced and generally adequate paramedics termed "code green" (mental patient) who was in DKA. Most paramedics know their code drugs cold, but couldn't do discharge teaching on sick babies, UTI's, or PID patients to save their souls. Standard EMS reply to this is, "Fine well do the codes; you do the UTI's," but the glitch is that trauma stabilization in the ED is a different critter in the ED than in the field and their training has focussed on the field. In fact, the focus of their training is pretty narrow when you consider the broad spectrum of what is seen in the ED. And you know what? I was that weird variety of ED nurse that LOVED it when my patients walked in looking benign and had something cool, subtle or outrageous going on. Post-ED I worked in a public health clinic where a kid presented with a sore throat. Ho-hum another sore throat. BORING, right? Well this one drooled with his sore throat. No thanks, I won't be needing that tongue blade. Referral to ED for treatment of his peri-tonsillar abscess.
NURSES, we have a knowledge base that makes us THE BEST deal for our clients. Don't forget it.
So, yes I am sure that paramedics will become even more attractive to hospital administrators and they are useful folks since they tend to think on their feet well, but being able to think on your feet DOES not substitute for an adequate data base of knowledge from which to work. Nurses who work with paramedics--and I did and I admired them and would have only wanted them to care for me or mine in an emergency situation--PLEASE do not forget, deny or deride what it is that you bring to this situation.