Spree now supports Pay Pal’s Website Payments Pro (US only.) This support applies to credit card payments only. Supporting actual PayPal payments will soon be included into Spree as well but that part has not been written yet. For some strange reason, PayPal has made it nearly impossible to effectively test their gateway. Fortunately I had an old test account laying around because I quickly gave up on all of the nonsense required to create a new one. In any event, the support is now there for those that want it.
Thanks to Will Emerson who contributed the code necessary for this implementation. Just a reminder about how gateways work in Spree. By default you will be using the Bogus Gateway when running Spree in development mode. This is regardless of whether you have a real gateway configured in your admin settings. In test mode, you will use whatever gateway you have configured in your admin settings but you will be transmitting to your gateways test server (Active Merchant handles the gateway specific details on how this is done.) When Spree is started in production mode you will be using the live production gateway.