I was going to post this same idea as a suggestion myself, but a quick search lead me to this thread.
I've played a lot of video games. I've never been affected by field of view in any way until I played Borderlands. Apparently, Borderlands had an abnormal FOV compared to most other FPS games and it gave me a pretty bad headache while playing. After some .cfg editing, I managed to make it playable and fixed my problem.
Cut to a few months later. I'm playing Minecraft and starting to get the same sort of headache/nausea. My fiancee thought the game looked fun, but after sitting down to play for a while herself, she had the same reaction.
Is there any chance that in a future build we would have the option of widening/shrinking the FOV?
This post is basically just seconding Dinnye's original post and letting Notch know that there are others out there who would like this feature.