How is PayPal different than any other payment method? It is basically a credit card processor.. One with a catchy name vs say those square iphone attachments some small businesses are using. If you're screwed on this, that has little to do with PayPal and everything to do with Kevin.
Argue the pitfalls of pre order all you want but I don't see PayPal being better or worse than anything else..by all means link it to your credit Card vs checking account though just as a layer of protection.