Pleading from the NiGHTS fan community has persuaded SEGA and Sumo Digital to include the flying jester in their upcoming kart racer, Sonic & SEGA All-Stars Racing.
He's not a playable racer, but appears as flagman, starting and ending each race. You can find a picture over at NiGHTSintoDreams.com (via Kotaku, thanks to Pete Brolly for the tip), along with a post from Sumo's S0L explaining that it was the fansite's impassioned requests that persuaded them to include the character.
"I have to admit the main reason he's in was after we saw your heartfelt pleas, especially those of DiGi and TRiPPY, we had to make sure NiGHTS was in and played an important role. After all, we really didn't want them to burn all their collection now. So whilst he's not playable, he very much made it in, and as a result of the huge amount of support for the character that you all showed."
S0L couldn't say whether NiGHTS would also appear as a playable character in future DLC: "That's a question I can't answer right now - it all depends on how well the game does."