You don't need to make zany/insane out-there shit for Midnight, people just want a solid roster of stuff.

>playable High Elves for Alliance
>playable Forest Trolls for Horde
>Void DH 3rd spec & 3rd Hero Talent tree
>Something else to continue class customization depth after Hero talent trees
>More than 4 zones would be very welcome
>2 raids at launch instead of 1 just for some spice & variety, can be 2 smaller ones (5 bosses, 3 bosses etc.)
>A Megadungeon at launch would be cool and a breath of fresh air
>Delves made more interesting than they were in TWW
>World content difficulty tiers & leveling revamp
>Bring back outdoor world farming relevance like it was in Vanilla, Wrath & TBC, make people want to do things outside of word quests.

This much would be easily be enough to get people to be genuinely interested again.