If Matt is the only one who knows then it doesn't give a good impression on the whole WP organization.
The way Jane, Aaron, Peter (westi), Otto, Mark Jaqtuith speaks of it it looks like its set in stone. No more input they have a group and thats it (Well there is this http://wpdevel.wordpress.com/2010/01/11/core-plugin-infrastructure/) . At least from my perspective.
The lack of understanding to other ideas are also concerning. There also seem to be some hybris going on regarding coding capabilities of core devs and those who are not core devs.

When checking wp-hackers list the only two really delving into the matter is Mike Schinkell and Jeremy Clarkson I think. And that was months ago. Not easy to find and follow discussions in wp-hackers I think.

From what I can gather it was all discussed and decided on WordCamp NYC in November.
Aaron says hes followed the discussion on various lists and places. I have had a hard trouble finding these discussions. I've posted what I've found in the wp tavern forum https://www.wptavern.com/forum/plugins-hacks/1192-proposal-core-compnents-plugins-4.html#post10998
If the discussion took place and the decision was made on a wordcamp then it aint exactly public and easily accessible to the rest of us.

Discussions and decisions seems to take place in A LOT of different places.
Why not figure out a way to tag stuff so everything regardless of source is shown on the same place? So we mere mortals and none core devs can follow whats going on and how the conclusions are made. And perhaps contribute in a more timely manner.