Most places that take paypal now take google checkout, but until ebay are forced to a) allow sellers to *not* use paypal and b) allow other online payment methods via their checkout, they'll never really make a big dent in Paypal.
Not to mention... giving people all of these options just confuses the fuck out of them.
I prefer "Enter Your Credit Card Number __________________ NOW!!!"
I've tested this exhaustively. FUCKING exhaustively.
One problem with paypal is their "safer, easier way to pay" bullshit. It makes my CC processor seem unsafe or not easy. Granted, I sell to consumers, and not webmasters, so I understand why webmasters like it.
But as for normal non-webmaster consumers, paypal resulted in abandoned carts because they undermined the safety and security of our own merchant account, and in addition, gave people more things to think about. They had their credit card in their back pocket, but paypal might be safer and their password is NOT in their back pocket.
I know it goes against conventional wisdom, but more payment options are not always better. I get better results by telling people EXACTLY what to do.
I'm no paypal hater, either. I base such decisions based entirely on what makes more $$ per visitor.