As I announced in the past I've attended the conference in Atlanta. It was the first event of a series in US and the organizers plan to have it annually in the same format. Below is my impression.
First off, it was a great success! To my knowledge it's the only conference which is vendor or technology agnostic. Not only it is cross-platform and cross-technology it's focused on the architecture issues and built for architects. Not developers or sysadmins but enterprise, infrastructure, and software architects.
Secondly, for a local conference (by the way, participation cost is just $500 which is absolutely exceptional for such events) there were about 250 participants that again demonstrates success of the first event. It was quite an efficient networking event to rub shoulders with local folks.
Thirdly, the keynotes speakers were real stars and they rocked! Angela, Mike, Scott, and Rick all presented a very valuable topics and were great speakers. A very sound composition of the speaker - another complement to the organizers.
Lastly, I advise you to go to the next event in Atlanta or other cities and wish IASA to rise the bar next time bringing new speakers and more participants.