DL has already announced all former NW aircraft will get new DL interiors.
I, for one, would be very surprised if the 744s don't get a full rehab very quickly. Long-haul international routes are DL's bread and butter.
The question for me is whether they'll go with the BE suites that are being installed in the 77 fleet, or the staggered lie-flats the 76s are getting.
I think nose-to-tail AVOD is a foregone conclusion, as well.