Google is including a host of other methods to sort as well, such as age, additional content and more. They're also incorporating means to add other type of data to stories, like a video or an image, on top of just a short description. They also play up the ability for the service to be used in conjunction with a mobile device, with “What's Popular” being used to trim down what you end up reading on your phone.
Don't feel alone if it seems a bit overwhelming and on the complicated side. However, given that Google walked away from a Digg buyout in the middle of last year, it seems they are intent on competing with them. Is there room for a Digg competitor?