We don't need Bitcoin to be accepted by retailers. All we need is a Ripple-enabled checking account that lets you hold your balance in Bitcoins. Then,
any merchant can accept Bitcoins (or any currency for that matter) - with no extra action required on their part.
My theory is that if ripple comes into use... it will allow the seamless transition between different currencies and people will then naturally gravitate to the most honest currency . Bitcoin!
If they did integrate bitcoin though I think that means they would integrate ripple if it came into use.