At last weekend's Tokyo Game Show, Dengeki and Sega revealed that they will be celebrating the publisher's 20th anniversary with crossover 2D fighting Dengeki Bunko Fighting Climax. Asuna from Sword Art Online and Shana from Shakugan no Shana were shown fighting in screenshots with SAO's Leafa and Wilhelmina from Shakugan no Shana also visibly participating in some capacity.
There's online chatter of Valkyria Chronicles representing the Sega side. Some of the many other currently unannounced Dengeki properties you might hope to see include Oreimo, Toradora, Index/Railgun, Spice and Wolf, Lodoss War, Kino's Journey, maybe even Azumanga Daioh.
The game will be playable at the October 6th Dengeki Bunko Fall Festival in Akihabara.