Felt continues to refine the IA lineup with the bikes you see here, internally called the IAx, but officially still just the IA. The new bike retains the aero design of the original, including tube shapes, integrated bento box, and narrow front end. See the complete article for lots more details.
The New IA
Internally referred to as the IAx, Felt's new IA frame slides in as a lower-priced alternative to the fully-integrated bike it released two years ago. The new model has a chassis just as fast (actually faster) than the previous bike, and standard interfaces to make life easier (and less expensive) for the end user.
The original top-tier IA remains unchanged other than getting a new paint scheme with the new Felt logo.