I went through the same questions after I graduated. I took a job in Med/Surg because I figured that it would be wiser for me to master my skills now while I was still fresh. If I had gone straight to OB or Psych, etc., then tried to change a year later, they will train you all over from the beginning just like a graduate nurse. So I just decided to get it out of the way now. I know I don't prefer MedSurg and am trying to move into something more specialized like PACU, ICU, etc, because at least with that training, you can pretty much go anywhere in the hospital if you feel the need to move.
I kind of think that all new nurses really should do MedSurg first. It's the only way to really get immersed into the full spectrum of skills and learn prioritizing, time mgmt, etc. But I also know that I am the only one of my friends who chose M/S so I guess it's a personal choice with the hospitals being so short staffed in some states.