Just to make sure we are on the same track - we are talking about one of the PCI-DSS requirements - having to use a PA-DSS certified solution in case you want customers to enter credit card details on your site.
Technically DPM implementation makes entering credit card details "out of scope" of your shopping cart, but at the same time the credit card details page belongs to shopping cart application and this is the fuzzy moment here - must that shopping cart application be PA-DSS certified or not?
Our QSA suggested that yes since the credit card form is generated by the application and this is the main reason we had to implement a separate "enter credit card details" page in X-Payment.
Looks like DPM makes meeting PCI-DSS requirements easier for a merchant (SAQ A instead of SAQ C according to gb2world's post), but it can't be advertised as a PA-DSS compliant solution (Auth.net doesn't advertise it so either). Neither DPM is a replacement for X-Payments in terms of "using a PA-DSS certified solution".
I am still not sure whether or not it can be a way to avoid having to use a PA-DSS certified solution.
I "+1" to gb2world's suggestion:
Originally Posted by gb2world
I always advise people to try and get the plans for compliance to be reviewed by the bank
Ask *your bank* before implementing DPM or anything else. PCI-DSS requirements are vague and different specialists may understand it differently.
and post your results here to help other merchants, too!