Kathy/Kate Kane and her alter ego, Batwoman, will appear on Supergirl as a recurring role. She will be Maggie Sawyer's ex, whose adventures as Batwoman occasionally take her to National City.
Barbara Gordon will also appear as Oracle (mostly so as not to have Batwoman AND Batgirl).
Babs will develop a strong friendship with Kara, Supergirl. The Oracle/Batwoman relationship is being modeled after the original Chuck Dixon Era Birds Of Prey, but with Kathy/Kate as the operative instead of Dinah.
Batman himself is still tied to the Gotham deal at Fox, but Fox has been approached to share the character for a fee. It would likely only be economically feasible if an actor playing Bruce Wayne and Batman were made a series regular across the whole network to defer the licensing costs to Fox.
Fox obtained the Batman and Gotham TV rights as part of a deal that included giving Warner Bros the go ahead to release Batman '66 on DVD. Even if Gotham were to end, they would retain rights as long as the DVDs were being sold.
John Wesley Shipp will be the third actor who will become a series regular across the whole CW DC Universe, after Wentworth Miller and John Barrowman. He will (obviously) be playing Jay Garrick, not Henry Allen.
Matt Ryan could get a similar deal as the network tests the streaming audience of Constantine as well as his appearances on the network this upcoming season. The Vampire Diaries is ending after this season and the network wants to keep Fridays as their horror night, probably pairing a Constantine-led series with workhorse Supernatural, which gets decent ratings whatever time slot it is moved to. iZombie is also seen as strong enough to lead Fridays with Supernatural if need be.
