This feature has being an option in certain European countries. Users are able to add Funds wallets via PayPal. On a report today Sony is adding this feature in the U.S
This option were added during the PSN maintenance. Head to this this link, sign in, you will get the “Add Funds to Wallet” option, then select PayPal. In a result for all that you will be able to proceeds the amount of $5, $10, $25, $50. The max is supposed to be $150.