I wouldn't presume to know what the field as a whole thinks, as I think views vary a lot from place to place and I've only spent serious time at a few universities. However, I can speculate based on the data I do have.

I think a sizable number (25%?) of AI graduate students I know are aware of LessWrong's existence. Also a sizeable (although probably smaller) number have read at least a few chapters of HPMOR; for the latter I'm mostly going off of demographics, I don't know that many who have told me they read HPMOR.

There is very little actual discussion of MIRI or LessWrong. From what I would gather most people silently disagree with MIRI, a few people probably silently agree. I would guess almost no one knows what MIRI is, although more would have heard of the Singularity Institute (but might confuse it with Singularity University). People do occasionally wonder whether we're going to end up killing everyone, although not for too long.

To address your comment in the grandchild, I certainly don't speak for Norvig but I would guess that "Norvig takes these [MIRI] ideas seriously" is probably false. He does talk at the Singularity Summit, but the tone when I attended his talk sounded more like "Hey you guys just said a bunch of stuff, based on what people in AI actually do, here's the parts that seem true and here's the part that seem false." It's also important to note that the notion of the singularity is much more widespread as a concept than MIRI in particular. "Norvig takes the singularity seriously" seems much more likely to be true to me, though again, I'm far from being in a position to make informed statements about his views.