The announcement was probably downplayed because there isn’t much you can do with it now. You can view your photos individually or play a slideshow. The interface is very sparse and its not clear if they’ll be adding more features to this down the road.
Check out your photos at lightroom.adobe.com
In addition to Lightroom mobile, we’ve also launched Lightroom web, a new way to view and share your images from any web browser. Available at http://lightroom.adobe.com.