For U.S. based buyers, yes, you can checkout using only a credit card without needing to register for PayPal. For many other countries, they now require you to register during checkout, but still allow you to use a credit card to make payment. Note that this is a change from the past few years where most countries could checkout directly with a credit card without registering. It goes back to a time in 2004 or earlier when this was also a requirement. It does indeed hurt their transaction volume, but they claim it is a necessary step to reduce fraud.