But if the buyer later tells Paypal that the product is Bitcoins and that is against there terms, is Paypal going to reverse the money, and then presumably shut down your account for TOS violation?
I'm just wondering if that works for most Virtual Goods but back fires with Bitcoins.
That I don't know for sure. But there's no way to prove the transaction was for BTC or anything else. Also PayPal has not formally made an announcement that BTC is against their Terms of Service. I still feel the currency clause in the ToS applies to normal fiat currency and not BTC. PayPal is only banning big dealers as far as I know. Unless there's other evidence proving otherwise that I missed.
You have the power to not deliver your BTC until you're completely satisfied with your buyer. This can consist of asking for emails confirming the buyer is NOT buying BTC, PayPal comments stating the same thing, opening a dispute and closing it "to show your buyer is satisfied after receiving the virtual goods all of a sudden."
I would worry more about a credit card chargeback than PayPal stopping you.