As you might already know, in Windows 7 you can also pin websites to the taskbar other than programs. So by clicking the pinned icon, you will be directly taken to that website thus avoiding the need for opening your browser and typing the URL or selecting the bookmark.
Sites can also take use of the jumplist feature to add certain custom options in the right click menu of the pinned item. You can read more on that here.
Hotmail has already implemented this feature since sometime. Now they have gone a step further to improve the pinned item feature by adding notifications of the number of unread emails since you last checked your email.
Dick Craddock the Group Program Manager of Hotmail stated in a blog post.
This week, we’ve been working on taking the next step and supporting notifications. Some of you may have seen this in the past few days, and we’re finishing the release of this feature today. This means when you’re signed into Hotmail and you’ve pinned it, we’ll show you a notification of how many new messages have arrived since you last checked your inbox.
This works like the mail tile in Windows Phone: the icon updates to show the count of messages that have been delivered since you last did something in Hotmail, and it clears when you do something in Hotmail like visit your inbox or read a message. So, now I can leave Hotmail open in the background while I do other work, and I can tell at a glance whether I have new mail.
This feature will work only if the newly released Internet Explorer 9 is installed.