I think Rian Johnson, Danny Boyle, and Neil Blomkamp are great picks for WW, Flash, and GLCorps not only because of their style and quality output, but because they are great at making movies on smaller budgets, which WB would want to take advantage of to avoid another GL2011 scenario.
Johnson's Looper was only $30 million.
Boyle's latest, Trance, is only $13 million
Blomkamp's SFX-heavy District 9 was only $30 million (roughly 1/7th of GL2011's budget, with arguably better SFX)
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Man of Tomorrow - 2015 : Zack Snyder
Wonder Woman - 2015 : Rian Johnson
style: new-52/Hellboy, with the camera movements/intensity/attitude of Haywire, Looper, & Only God Forgives
The FLASH - 2016 : Danny Boyle
style: Spiderman/Ironman-esque origin story, which we haven't got in a while, but shorter/faster/crazier with Boyle's kinetic camera/editing style and sweet/uplifting ending (ala Slumdog/127 hours), and the clever and contained time-travel story ala Looper
The Batman - 2016 : Fincher, (if there's a reboot)
style: Fincher-esque introspective detective story, ala Se7en, Fight Club, Dragon Tattoo, etc
Justice League - 2017: Brad Bird
King of Atlantis - 2018: Rupert Wyatt (Rise of the Planet of the Apes), or Peter Jackson, who doesn't seem to have anything on his plate; his involvement would be huge. It also seems like the kind of epic scale property he might want to take on.
Green Lantern Corps - 2019: Blomkamp
style: Elysium / Star Trek '09
Heaven Sent - ?: Del Toro