I just thought that I'd add my thoughts to the current frenzy of analysis and speculation regarding the Fallout 4 Teaser Trailer. Take this as seriously or as lightly as you wish:
The leaked script, if accepted as accurate, confirms that the protagonist is either the father or the mother in the family we see in the trailer (I suspect that if you select a female character, then the protagonist is the mother with a suitably-modified script and a female VA). My guess is that he/she is an employee of Vault-Tec (thus the Vault-Tec poster in the kitchen/dining nook) and thus had a guaranteed place in Vault-111.
More importantly, the