A:CM did not make an appearance this year at E3 despite what many websites presumed. My guess is that Gearbox is too busy focusing on the upcoming release of Hell's Highway on August 26. After that, I'm sure they will focus getting the word out for A:CM.
It's funny. Now, I only care that Hell's Highway gets pushed out to retail on time so that A:CM feels that much closer to its own release date and finally gets some updated PR of its own.