[font="comic sans ms"]my gut feeling would be that with your or background, you would have an easy time switching to that should you decide the micu is not for you.
going the other direction might not be so easy.
in general, i think i would avoid the or as a new grad unless you knew that is what you wanted to do. nursing skills in the or are very different than those used in the rest of the hospital. there are many nursing skills you don't use in the or, like giving tube feeds. a skill you would probably use every day in micu, but i'd be surprised if you ever had to use that skill in the or. while there are a whole host of other skills that you will use in the or but probably never on an inpatient unit, the or is used to training people to those skills. in-patient units are not really accoustomed to that -- "what do you mean you've never given a bolus tube feed before?"
when i worked in icu, i remeber precepting a girl who had several years of experience as a nurse, all in or and pacu. there was a whole bunch of things she had never done, and i wasn't used to precepting someone where i had to explain so much about stuff that just seemed routine to me. it wasn't a problem, but i remember thinking how much harder it was for her to go from or to icu than it was for our new grads to adapt to icu.
so if you really are ambivilent, or even leaning towards micu, that is where i would go. however, if you really want to go to the or (and have no desire to ever give tube feeds
), then stick with your heart and go there.