I'm an OR nurse and I love it. I would never leave the OR. I work with many nurses who have left the unit to come to the OR such as Emerg and vice versa. I feel that your skills that you learn in the OR would apply in any other unit such as your assessment skills, your organization skills, team work just to list a few. I do admit we don't give meds, so if you return to the unit you'll have to refresh on your meds and giving needles, but as i remember you study your meds the night before and landmark and you still gave it the next day. So I don't think it would be hard to refresh that skill. I also think that no matter what type of nurse you choose such as a med-surg nurse or ER or ICU...there's always will be a learning curve. Secondly, as a new grad you are in high demand and by that you can get a job anywhere like ICU places that required you to have several years experiences and additional schooling, but now they are desperate and will take anybody(at least in Calgary, Alberta CANADA). So if you decide the OR is not for you, I bet any unit would be happy to take you and the worst case is they will give you some additional training to get you going.
I'm bias. I think you should be an OR nurse and I bet you'll love it and if I'm wrong then I guess you be an ER nurse. Either way good luck with your career.