I don't think they will sell IP's. Maybe they will license out properties to other publishers so they can publish characters (like say, a Vixen comic published by IDW) and they might license out properties to other studios so they will make movies and tv shows *for* WB/DC.
I should note that this is a similar situation that Marvel was in in the late 90's and early 00's. They were bankrupt and sold the rights for adaptations to various studios; Fox got X-Men, Sony got Spider-Man, I think either Paramount or Universal (?) had Namor and Universal still holds distribution rights for Hulk. It took a good 20 years and one of the largest corporate mergers in history before Marvel got the live action rights back to their characters.
I don't expect history to repeat itself but the next couple of years are going to be rough for DC fans.