Some of you may remember the Playstation Network outage that occurred a while ago, but many people are still leery about putting their credit card information into the Playstation Network directly.
Sony and Paypal have finally come to agreement to allow the option to pay for things via Paypal on the Playstation Network through your console, so now you have the option of using that as a form of payment instead.
Paypal payment was available on the Playstation Web Store (via your computer or whatever) but is only just now available directly on your Playstation devices.