@tekzt - You're correct. Most of the development for the service was centered around getting the Ping service to work as quickly as possible since at one point in time, sending out the pings became the slowest point in actually publishing a blog post. I think the Ping-O-Matic website is just a sign of what was. I was thinking about the site just disappearing while leaving the service available to use through the RPC link but then, people outside of WordPress would not be able to easily use the service which is probably why the site is still online.

@Chip Bennett - When I submitted my sites on the Ping-O-Matic site, all of the pings were sent just fine although I don't have any details as to whether or not the sites received the ping update.

Do you guys know if your blog sends out pings if you simply update a post?