Why scheduling posts in the past
I noticed this by chance: scheduling posts in the past is the fastest way to ping them across services. Feeds update immediately, while publishing live and/or in the future requires some minutes.
I don’t think that this applies just for WordPress, because the main advantages come from FeedBurner: it notifies Twitter faster with the Google’s URL Shortening service — in the form of http://goo.gl/fb/foo.
I didn’t notice any affection for the Facebook’s notes (I use Twitter Feed to notify my fan pages), but I’m pretty sure it works for Technorati too.
Just “pretty”, because I’m still waiting for this blog to be reviewed as needed by the new claiming method. I don’t like it at all… anyway, you only need to schedule your post some minutes before.
