One of the fundamental parts of paypal is the ease in which a transaction can be reversed if the customer is not pleased. Bitcoin transactions are irreversable. Many websites that currently accept paypal may be cautious about this. So that means Paypal will have to take the heat if something goes wrong in a transaction. Something I don't see happening.
That's a very good point raised. Even if they act as an escrow service, charge back could still take place 1 month down the road especially when some for items that involve international shipping, that would take even longer and changeback could still happen more than a month after that. So they can't just hold on to the bitcoin for that long because once released it is not reversible. After reviewing the point, yeah, I don't think we'll ever see a paypal bitcoin currency account for that matter