techno weenie | RFC > Common XML-RPC API for Weblogs:

"This is an RFC for a common XML-RPC interface for other weblogging applications. The Blogger and Manila interfaces are fine, but are written specifically for those two applications.

Interesting. Looks like Conversant's XML-RPC API could easily support the Common Weblogs API - which includes a 'subject' capability!

Like Jim says the lack of a Subject: field in the current implementation of the Blogger API is a major drawback for those of used to these things (in Conversant ;-))