That has always worked for me on that page. I want them to be directed to the cart as soon as they add something from the home page or catalouge page.
This is how many popular online line stores work, you want to drive them to make a purchase as quick as possible. On the cart page I have upsells and additional items, along with a continue shopping button.
By just placing a check mark or changing the button to say "Added" there is no real action for the customer. And if they want to check out at that point, how can they??? If you click the checkmark it does nothing, same thing for the button. They need to search for the cart link which can be frustrating for a first time customer.
So the most intuitive thing to drive sales is to either have it go directly to the cart or have something that post back next to the checkmark, like "View Cart".