(Thanks to Jed Brown for suggesting this)
One of the more popular new features in Microsoft Outlook 2010 is the Ignore Conversation feature. With one click you can delete all of the messages you've received in a particular conversation (thread) AND Outlook will automatically delete all future messages you receive in that conversaton for a period of 60 days.
However...recently somebody wistfully observed that they wished the Ignore Conversation feature would mark the messages as "Read" before deleting them. Otherwise you get an unread message count on your Deleted Items folder. Big deal? Probably not, but it's a little unsightly.
There is, as Jed pointed out to me, a workaround though.
Instead of using the standard Ignore Conversation feature, create a Quick Step that marks the messages as read and then Ignores the conversation and use that.
Maybe we'll see this nuance baked into the Ignore Conversation thread in the next release of Outlook but for now you can use this workaround if you don't want to see them on your Deleted Items counter.