I'm planning on using this to purchase Mass Effect 2, Dead Space 2, and some other Origin games that I've been eyeing.
EDIT: It looks like these can be used for physical games as well, and this is a great way to take advantage of the sale while using the GS credit many of us have amassed recently.
EDIT, 2: Some people have reported having trouble using a combination of EA credit and a credit/debit card for their transaction. So far, it looks like you can do this, but it must be split into two orders. Place one using just credit, and then you'll be able to place a second order using both credit and a credit card without any errors. I don't know why it works, but it just does.
Edited by Slim Gatsby, 19 March 2012 - 06:07 AM.