Google is adding PayPal as a payment option for Play Store purchases starting today! Just tap through on a purchase and pick your new payment option. The roll-out is just starting today though, so it might take awhile to to live in your area. These are available in 12 countries, including U.S., Germany, and Canada. In addition, carrier billing and Play Store gift cards are getting expanded international support, so they're now available in 24 and 13 countries respectively. Speaking of currency and going international, developers can now sell in 13 new countries and added 28 new currencies.
Getting PayPal as a Play Store payment option is a big deal and a long time coming. Between this, carrier billing, and Google Wallet, there's just about every method of paying for apps you could possibly want. Increased international support is great too, of course.
Source: Android Developers Blog