I graduated last June as a Banner Fellow. I love love love Peds so I was chose to precept at Cardon Children's. When it came time for a job (only 1 of my 28 classmates turned their preceptorship into a job) there was and still is nothing in Peds for new grads. As a Banner Fellow, they sent me out on almost a dozen interviews for all kinds of units and the fact that I precepted in peds really hurt me.
You have to understand that when you do get an interview, you are competeing (sp?) against many other people and the manager wants to hire someone who is passionate about their type of unit (oncology, med/surg, tele, etc.) so that the new grad will stay on that unit for awhile, not just move on once they get the experience. So when I went in to PCU saying that the heart really interested me, but oh yeah, I precepted in peds, well, they knew where my passion was. And ever single interviewer asked me where I precepted.
My advise is to go med/surg. Managers know that preceptor spots are limited, so if you precept med/surg and then get an interview for a specialty, you can blame limited spots. Plus the med/surg experience will give you the stories that managers will ask you about in an interview. I guess I am trying to say that you'll be well rounded and that new grad jobs are rare and speciality new grad jobs are just about impossible (except maybe if you already work on that floor as an aide or something). Good luck!!