Your friendly neighborhood lurker here.
I was lucky enough to get into the first round of play testing, and have been sticking with it ever since. While I am limited in what I can say about it I would be happy to answer questions to the best of my ability. First, the short version: the Atomic Robo RPG is being built on the yet unreleased Fate Core system. The primary designer is Mike Olson who was hand picked by the Atomic Robo people due to their interest in his work on the FATE edition of Kerberos Club.
Based on my experience thus far the game is coming together pretty solidly. The underlying Fate system has been streamlined, and smoothed out. Much of the design work has been focused on providing players with the tools to make the game elements with a few examples of each component. It is by far the lightest Fate iteration I have worked with, though I am not clear on how much it will grow before going to print. The system builds on the Fate by adding in a few thematic wrinkles to support the Atomic Robo feel. My favorite such wrinkle is the "Brainstorm" which allows players to compete to create a hypothesis about scientist nature of "the big bad" which can strongly influence play.
Another feature I like about the game is the "E-Z No Math Character Creation" which is a mode of play that allows players to basically start with a concept, a few skill sets (called modes) and start playing. Throughout play you actual develop the character as you learn more about them. This works great for the non-linear nature of Atomic Robo, because it allows you to say, "hey Jim isn't here tonight, so lets jump back thirty years and do an adventure where we learn the origin of Villain X. Who has some character ideas? Etc..."
I've collected a quick series of links that readers may find useful getting a gist for the game below:
Press Release
http://www.deadlyfredly.com/2012/01/atomic-robo-wears-the-evil-hat/
Interview on Critical Hits
http://critical-hits.com/2012/01/23/interview-atomic-robo-the-roleplaying-game/
Podcast Interview on BAMF
http://mikelaff.podbean.com/2012/01/24/atomic-robo-rpg/
Podcast Interview on Bear Swarm
http://www.bearswarm.com/episode-213-a-conversation-with-mike-olsen
Author's Website
http://spiritoftheblank.blogspot.com/
Publisher's Website
http://www.evilhat.com/
Edit: Fixed spelling of Mike's name, and fixed Bear Swarm Link