The angled coach seats are something that have been tossed around for decades now as a way to cram in more seats. However, in the past it could not be made to work because of the way seat rails are installed, the seat strength requirements, etc.

I think what has happened is seat structural material technologies have finally caught up with the concept.

With ultra-long range flights being more widely flown, and with the realities of DVT and other long-duration medical issues, and $100+/barrel oil dictating higher passenger densities (i.e., 9-abreast coach seating in the 787), something has to be done.

Imagine flying in the back of an Emirates 777-200LR from DXB-IAH. 16+ hours at 10-abreast at 33" pitch. I did 8 hours on an Emirates 777-300ER from DXB-JNB at 10-abreast and 34" pitch, and it sucked. I've done 15 hours overnight in a 747 from LAX-MEL twice, and it is amazing what a difference a half an inch wider seat makes. The only thing worse than 10-abreast on the 777 was 10-abreast on a charter DC-10.

9-abreast on a 777, 7-abreast in a 767, or 10-abreast in an A380 is good for economy class. 10-abreast in a 747 is tolerable. 10-abreast in a 777 is not fun and 9-abreast in a 787 is not going to be fun.

I for one welcome more comfortable Y seats. I am not so anal-retentive or OCD to be bothered by a lack of orthogonality in alignment.