[wp-hackers] XML-RPC - are there any APIs should be supported

[Eitan Adler]

Per http://codex.wordpress.org/XML-RPC_Support only three (+1 for
wordpress) APIs are supported.
Is there anything I could to improve the XML-RPC implementation? Are
there any services that support XML-RPC that might be useful to have
in wordpress either as a plugin or in core?
Perhaps a plugin for http://www.xmlrpc.com/weblogsCom ?