Thanks for the references MMZ... I was drawing a blank... I knew that Yama, Ukitake, Shunsui and Unohana were all at least 200+, Yama is def. older than the rest... since he founded the Shinigami Academy.
Matsumoto was a shinigami before Hitsugaya... its the 2nd movie... I'm pretty sure thats where we find out that she was a shinigami first.
Needless to say Hitsugaya is the youngest captain in more than one way... age wise and time wise.... it'll be interesting to see if we get to see him grow even more. As Shunsui tells Stark, Hitsugaya is young and has a way to go in development. I'm still curious to see what Shunsui's shakai and bankai powers are :P