Retrobit have had a wireless Dreamcast controller slated for about two years now but because of the old Megadrive/Genesis era Welcome to the Next Level reference I am guessing it has something to do with that period in Sega gaming.
I think I remember when sega changed designs to use colours in the art work the genesis had red as its spine edge colour (the colours seemed more of a US thing and i'm in the UK so can't be sure as late Megadrive games had a blue design) so again it makes me think it's perhaps related to that.
I'm just hoping it's not just a red version of their megadrive controller as that would be kinda boring.