I received my invite to participate in the OmniFocus Mail Drop service today. Signed up and started firing tasks to the inbox. Works great, with almost no delay. My only gripe so far is that mail messages sent to your Inbox via Mail Drop are not given the super handy like directly to the message in your Mail.app or Postbox. While that is a bummer, I do see that the system will be handy if I am away from my Mac and want to add something to the inbox.