It is already in place. There is no separate section of seating for Basic Economy. A Basic Economy ticket is more restrictive and lacks the ability to pre-select a seat in coach, but it is still a seat in the main coach cabin. It was mostly just a rebranding exercise. Much of it already existed (including Basic Economy tickets) under different names. Comfort+ was formerly Economy Comfort and Delta ONE was formerly Business Elite. Details at the link below.

http://www.delta.com/content/www/en_...t-options.html