I got the "nothing in the seat pockets" speech last November but only in the exit row seats for those immediate passengers. Not even a book was allowed.
And if lucky to get 12F, I use the under-seat space where 11F would go, chasing out 11E's stuff if necessary.
And if the flight not full, who doesn't use the middle seat for laptop, headphones, Mp3s, books & food/drink storage anyway? Only if its a bag have I been asked to put it under.
Being a window dweller, its an inconvenience to ask 2 people to move every time I need something.
Me thinks we are going a bit overboard here. Should there be an "non-traditional" landing with enough force to propel things out of the seat pocket, all those items at our feet are going to move as well. This will be the least of our worries...