The argument is that this will make WordPress more secure out of the box — but the question is at what cost? And, is there a better solution to this problem rather than disabling features and functionality (even if only a small subset of users currently make use of these APIs) if the changes end up being short-sighted?
Heck, Stephen Paul Weber already got OAuth + AtomPub working for WordPress, and has completed a basic OAuth plugin for WordPress. The pieces are nearly in place, not to mention the fact that OAuth will pretty much be essential if WordPress is going to adopt OpenID at some point down the road. It’s also going to be quite useful if folks want to post from, say, a Google Gadget or OpenSocial application (or similar) to a WordPress blog if the XML-RPC APIs are going to be off by default (given Google’s wholesale embrace of OAuth).
Now, fortunately, folks within Automattic are supportive of OAuth, including Matt and Lloyd.
There are plenty of benefits to going down this path, not to mention the ability to scope third party applications to certain permissions — like letting Facebook see your private posts but not edit or create new ones — or authorizing desktop applications to post new entries or upload photos or videos without having to remember your username and password (instead you’d type in your blog address — and it would discover the authorization endpoints using XRDS-Simple — Eran has more on discovery: Magic, People vs. Machines).
Anyway, WordPress and OAuth are natural complements, and with popular support and momentum behind the protocol, it’s tragic to see needless reinvention when so many modern applications have the same problem of delegated authorization.
I see this is a tremendous opportunity for both WordPress and OAuth and am looking forward to discussing this opportunity — at least consideration for WordPress 2.7 — and tonight’s meetup — for which I’m now late! Doh!