What did I hear?
Mostly, STAY AWAY FROM RHYME. An agent from Sheldon Fogelman Agency had this advice:
I would caution against using rhyme, which can lead to using words that are a better fit for the rhyme scheme as opposed to the narrative. It only takes one false rhyme to unravel all of the magic and rhythm of your story.
On this front, I am not at all deterred. I am quite confident in my ability to write in rhyme.
Another thing I heard from at least two sources is that it is getting harder to sell a PB manuscript unless the author happens to also be an illustrator.
This I found rather depressing. (No amount of confidence in the world is going to suddenly make me able to draw!)
The last comment that I heard repeatedly during the first page session was to "up the stakes". Take it up a notch. Go overboard even.
That one I will keep in mind as I work on new picture book manuscripts.