Another point: Stark got taken down (as in, he goes into a seizure) by a Skrull computer virus this month; maybe community security experts could've found and corrected the problem with his biotech if he had open-sourced Extremis ;)

Something this article kinda downplays: the modern depiction of Iron Man post-Extremis is very post-human. Warren Ellis' Extremis storyline filled Starks body with various nano-gizmos giving him the ability to remotely command technology with his mind, even without the Iron Man suit, and most of the dialogue and plot revolved around Stark wrestling with his arms dealer past while using the profits and experience that gave him to bring "the future [...] the earliest stages of adapting machine to man and making us great". A documentary filmmaker challenges Stark to justify how the Iron Man armor helps the kids who've had their limbs blown off by his mines; it's all great stuff.

That said, yeah, Stark probably wouldn't be a great fan of open-sourcing Extremis or Iron tech.

There's an open source version of Blockout available also (although there are no Mac OSX binaries handy offhand):

http://www.blockout.net/blockout2/