Very solid article from TheDesignAir about the state of the business class seat and its square footage. 

So it isn’t often we think ourselves as that awkward L-shaped brick from classic computer game Tetris, but fundamentally that’s how aircraft seat designers see us. Unfortunately-shaped wedges that have to fit neatly into a rectangular shape. In a constant fight to give airline passengers more space, more comfort and a better quality experience, the war of the seat configuration continues.

The BA patent raises some interesting question about the optimal use of the cabin to seat ever more premium seats.

It's a delicate balance between comfort, privacy, access and revenue per seat (and their number per cabin).