Delta just announced a promo for earning Medallion Qualifying Miles (MQMs) from Hilton stays. Your Hilton account must be set up to give Delta miles. If you opt for the variable mileage version, you get 1 MPM/$ up to 10,000. If you get the fixed mileage version, it's 500 MQM/stay. Only stays of two or more nights count.

Must register via this page first, but apparently not targeted.

There will probably be some discussion in the Delta forum, though nobody's started it yet, but it seems to fit this thread too.