Basic 9 points Corsair does not have any ranged weapon or additional weapon.
They don't even have existence. The "option" for either 2pts handbow or 2pts AHW is mandatory.
I think DEs will start with a standard faceroll hammer units like Witch elves with Cauldron and big Executioner units which will be supported with some chaff and Dark+Life casters.
But eventually the best players will go to MSU style. Characters on Pegasi, small units, chariots and tons of Dark Riders and two Warlock units (which are THE unit of the new book, best fast cavalry in the game). New monsters are all around 180 points which further makes them viable in MSU lists but I fear you will have to saturate the table with them to make them viable. Taking only one or two will be the same as giving enemy free points.
I foresee one khainite build with 1 large witch elves, 1 large exec, 1 COB and fast cav.
The other build will be made by MSU indeed, but the units are not yet best selected.
Lords: Sorceresses (dark, life, shadows), Dreadlords on dragons, Hellebron if special characters are OK. Possibly the beastmaster on chariot or on manticore, time will tell.
Heroes: sorceresses (beasts...), BSB. The COB only for khainite builds.
Core: Corsairs with AHW are great, witch elves too, but the best core is fast cav with repeater crossbow.
Special: 4 bolts throwers will be the norm. Else, very hard to tell. Executioners are excellent, Shades are as good as before. Hydras are weaker than expected.
Rare, the fast cav seems a favorite, the K-monster seems not too bad.