In my working branch today, I got a json remote package search working. It might be a little rough, so check it out if you are brave.
Currently in my 'testing' branch.
I have some test code here: http://www.archlinux.org/~eliott/zomgstuff/rpc_examples.tar.gz
For testing, make sure you configure the target url manually in the respective python or html file(s). The python version is VERY SIMPLE. Just edit the file and run. A more robust test harness could probably be written with the python one...that takes some command line args and such.
Anyway..my hope is this may be useful for some of the people that have command line tools. JSON is alot easier to parse than scraping the html output....