No word on DLC if only because they can't jump the gun just yet, even though a lot of time has pass. They don't want there to be situation where they say "yes it's coming!" and then something happens along the way where they can't actually go through with it and say "sorry, it's not happening". They are probably taking a while because they have to acquire (or reacquire if it's a character that appeared before in the last racer) the license to use them. Remember, most SEGA IP's weren't actually developed by SEGA.
http://backloggery.com/SetnaroX "Proper sound shatters glass. Proper sound shatters the Universe."