“With the new Google Reader gadget, you can now track your feeds and Google Reader subscriptions directly from your desktop. The Google Reader gadget is designed to be familiar for existing Reader users, yet compact like our other Desktop gadgets”.
To get started, download the gadget (you might need to install Google Desktop first) and sign-in to your Google account. If you select a subscription, your gadget will update automatically with new posts. Clicking an item opens a larger view where you can see the item preview and perform familiar actions such as star, share, and email. Due to a technical limitation of Google Desktop gadgets, full HTML feeds won’t render fully, but clicking on an item title will take you to the original website in your browser.
Source: Google Reader Blog