If you are the DVC Member, you can book DME on the Members website or with MS. If you are not a Member but a renter, the DVC Member needs to book DME for you.
as far as i understand it, ME is not included in the price for DVC.
OTOH, DVC resorts at wdw qualify for onsite resort benefits, like EMH and ME...so while those perks are being offered to onsite guests...they are also offered for DVC resort stays. if disney stops offering ME for onsite guests, i don't expect they will continue to offer the service for DVC...it could change at any time...
I just got off the phone with MS regarding a stay next January at AKV. She told me to call in advance to MS with my travel information if we wanted to use ME. So it's still included with a resort stay.