Fallout 3 - Informal Q&A @ RPGamer

Bethsoft's Emil Pagliarulo answered press questions during the Fallout 3 presentation and RPGamer has assembled them into a short article-format interview.  Here's an excerpt:

When asked about whether or not it'd be possible to kill any and all NPCs, Emil expressed their concern over letting their players get backed into a corner that they can't get themselves out of, or not experiencing content the designers want to be sure they see. So it's currently still being worked out whether or not they'll be able to design the game such that they can let you kill whoever, or if they'll have to make some people untouchable. He did express a strong desire to have as few unkillable NPCs as possible, as they know the negative aspects of putting walls like that in front of players.