I started experimenting with something similar (although got nowhere) as a helper for getting back to Inbox-0 from an overflowing inbox. The concept was fairly

I started experimenting with something similar (although got nowhere) as a helper for getting back to Inbox-0 from an overflowing inbox. The concept was fairly similar, go through the inbox and sort it into piles of important, replied, unreplied, deletable, twitter statuses etc, and then the user could deal with archiving/deleting/following up more quickly. This looks like a much better solution however, something running the whole time and stopping me getting into that mess.