My ultimate pipe dream for any Sega announcement is the news that they ripped the engine from Dengeki Bunko to make a Sega crossover fighter.
I've always wanted to see how Sonic would work in a 2D fighter like that, besides which they have a lot of really cool and unique IP's like Virtua Fighter/Fighting Vipers, Valkyria Chronicles, Space Channel 5, Jet Set Radio, Sakura Wars, Shenmue, House of the Dead, Resonance of Fate, Shining Force, Dynamite Cop, etc.
And then if they made Segata Sanshiro the final boss it'd be perfect.