I thought I'd reply to Bob's (and to some extent Megan's) comments on my narrative voice post here since my response is likely to be long, meandering and drawn out and, thus, not terribly suited for the narrow comments page.
Bob asks, "What about voice with gravitas? Why are so many writers terrified of sounding serious?"
I don't know that they are, but you're right that there is a trend in fiction right now toward a chatty, first person narrative voice. I suspect part of that is because the target audience (the slacker generation and younger) tends toward sarcasm and meta-fiction in their life and entertainment. Thus, it's an easy way for a writer to establish a rapport with her audience. Plus, I think a lot of writers enjoy the challenge of working with a potentially unreliable narrator. It's fun to try to figure out how to let your readers know the truth about a situation when your narrator is lying to him/herself about it, you know?
But, I think you can have a serious narrative voice. What I was trying to caution new writers about is being careful of the distinction between serious and flat. You can be plenty serious, but still have that view color the way you look at things. A serious narrator will still "notice" things that are important to him/her as they reflect plot or character. (Example: hero is space captain going for job interview. When he walks in the room the thing he might first notice is the cheap veneer on the table... or some other clue that will forward, in many ways, the plot, as it will dictate how he responds to the scene. This can all be described seriously, but I think it still ought to be a filtered by his personality and situation. A flat narration would simply start listing the dimensions of the room, the table, the color of the walls, etc with no regard to how the character might be reacting to any of it.)
I disagree with Bob about omniscient p.o.v., in that I don't see omniscient as lacking a personality or distinct narrative voice. In fact, the omniscient p.o.v. is merely a character outside of the story who can see into other people's heads. A good example of this is almost any sort of mythological or fairy tale like story, in which the narrator basically directs the story to the moral that he or she is trying to make. Sometimes they're _not_ invisible in the text, they might break out with an imperative sentence like, "Imagine!" or a comment directly to the reader, like, "This was before you were born, and so things were different then." A great modern writer who uses omniscient well is Eleanor Arnason.
Certainly, Bob is right when he says that it is possible that pumping up the voice won't help every writer who has been told that their writing is flat. I agree that it's likely something more holistic. However, I have read at least two manuscripts from students of mine who did everything else right, as far as I could tell, but there was still something that felt missing. I spent months mulling over the problem, and finally decided that what I thought the manuscripts needed was a better sense of voice.
But, voice as a concept is no trendier than the idea that a sentence must include a verb.
How voice is presented has changed dramatically over time, but fiction has always had a voice. Why? Because fiction in its primal form was spoken. Stories have always been told by SOMEONE. This doesn't change because they are written down.