Seems I spoke a little too soon recently about the ease with which the 
current The Weekly Squeak blog ( http://news.squeak.org ) RSS could be 
switched to JSON from XML. Yes, there is a plugin that aims that way. 
But it appears that is more for people who deploy Wordpress themselves. 
Not so much for people who just use it for free with Wordpress doing the 
deploying.

Unless I misread these:

https://developers.google.com/blogger/docs/2.0/json/getting_started#background
http://code.blogger.com/2011/09/blogger-json-api-now-available.html
http://beautifulbeta.wikidot.com/json-feeds

it looks like Blogger has a JSON API what with it being Google and all.

So, the way to switch from a squeak.org that receives The Weekly Squeak 
as XML to JSON looks easiest by switching from Wordpress to Blogger. 
It's a thought. If somebody has a better grip on this, I'd love to hear it.

Chris