thanks all for the comments and ideas!
to be more specific, I got a verbal "welcome to the team" from two nurse recruiters and the ADN of the ED. the ADN actually told me she also hired so and so from my school, as well as two others from different schools and she's convinced that we're all going to make a "great group of RNs on the unit" - so everything is telling me I'm hired EXCEPT for the official offer letter. the nurse recruiter even spent about 30mins on the phone with me explaining all the benefits, salary, union details, etc. BUT, as I know, it all comes down to the offer letter which I haven't gotten so yeah, I'm not counting my chickens before they hatch.
The nurse recruiter told me the process is that HR has to review all my documents, do the background check and call me in for a physical and assuming everything is good, then they give me an offer letter, but in the past at other non nursing jobs, I've gotten an offer letter CONTINGENT upon my background check and drug test, meaning it's null and void if both are not spotless, so yeah, I find this a little odd and wanted to know if it was commonplace in nursing.
I am continuing to apply and (hopefully) interview at other places though - on one hand, the hospital that has kind of verbally hired me is a city hospital in a rough neighborhood and not necessarily my first choice of facilities, but on the other hand, they're placing me in the ED which is rare around here (usually you need at least 2 years experience) and I already have experience working there and love the team. The benefits are great and the salary isn't bad either, it's just the rough neighborhood and some of the patients.