Scott Berkun, team lead at WordPress.com, announced a new feature at WordPress.com recently: email notifications for post “likes”. As Berkun describes:
We’ve added two new email notifications, one for likes and one for subscriptions.
Post authors will receive an email notification from WordPress.com, telling them which post was liked and who it was. And blog owners will receive an email when someone new subscribes to their blog. This gives instant feedback every time your post or blog gets some positive attention.
This is a WordPress.com hosted blog feature only, since the “like” feature is a WordPress.com feature only. If you are on a WordPress.com blog you are likely enjoying this feature right now. If you don’t want email notifications, you can disable them under Dashboard→Settings→Discussion.