There was a specific discussion about trashed items and blog clients ( see this ticket for some reference - http://core.trac.wordpress.org/ticket/11303 ). The challenge came in that the client applications didn't know about trashed items, like posts and comments, so they would show up as normal posts and comments.

At the time I pushed for not exposing trashed items to clients. I chatted with westi about this and we agreed (at the time) that most (all?) clients wouldn't know how to properly handle trashed items, so we hid them. With the intent that we'd revisit this item later.

Given the already massive amount of work for the merge in WP3.0 I don't think this is a good time to re-visit this. This might be something good to take on in WP3.1.

When we start down that road we'll be shouting it from the roof tops so that we give the blog client authors as much heads up as possible.