"self-publishing" and "use retail console as a dev/debug/test/whatever kit" are technically two separate things. Self-publishing doesn't necessarily imply the latter (though using the retail console to develop on does imply the former). It could either be:
1) the small to moderately sized developer that has an office, full staff, etc., and can afford a devkit, but doesn't want a separate publisher, and wants to maintain control of their IP
2) the random person in their bedroom who just wants to mess around making Xbox One games by themselves without needing to get a bunch of money for a devkit. (basically, what XBLIG was already, but with discoverability improvements)
The announcement does seem to support 2), but I'm curious if 1) is also in the picture (which is where your Lorne Lannings would come in).