There will be no more newcomers
The rocket Segata Sanshiro rode to his death and in the Race of AGES was launched by Sony by proxy of Sackboy.When we last saw Segata, he sacrificed his life to save the Dreamcast from a rocket launched by one of Sega's competitors, whose identities weren't disclosed. Given than LittleBigPlanet Karting is the direct competitor to to All-Stars Racing Transformed (so much that Sony denied Sega permission to use Sackboy as a Guest Fighter), it seems plausible that Sackboy took a tip from his masters years ago and attempted to blow up the race with the same rocket to achieve total market domination, only to be denied by the same person who foiled them before. Sackboy is a Not-So-Harmless Villain, is he? (... give or take that one time he attempted to befriend a Little Sister.)
In Transformed, Sonic is Turbo.Presumably he followed Ralph out. It'd explain why he never leaves his kart and runs.
Joe Musashi will ride on a motorized/mechanized Idaten from Shinobi III in the eventual third All-Stars Racing title.What? Date Masamune isn't the only guy with the chops to ride on a motorhorse. Plus, with "Idaten" already being featured as half of the theme for Seasonal Shrines in Transformed, you'd figure its namesake would show too, right?
Similarly, Eggman will be riding his Drill Eggman from Emerald Hill Zone in Sonic 2 (sans the drill, maybe).Honestly, I can't believe this hasn't happened yet. For bonus points, maybe it morphs into another one of Eggman's numerous boss vehicles for its All-Star.
Green and Seven Force will make an appearance in the next game.Now, yes, Gunstar Heroes is a Treasure IP, but the original game was released on the Genesis and was featured as part of Sega's Sega Ages line of compilations and re-releases. And with the transforming vehicle mechanic introduced in Transformed, Seven Force is a no-brainer. All they have to do is scale it down a bit. By any means, it makes a bit more sense than say, Danica Patrick or the Team Fortress 2 crew. don't sound like themselves, as the Spy could just be enjoying the adrenaline rush gained from the race a little too much to worry about keeping their voices as well as his own improbable accent straight.
Transformed will be the last game to feature, outside of a Classic Cup track, Seaside Hill as a locale.Regardless of Heroes' somewhat mixed reception among the fanbase (personally, I actually liked it), the resurgence of Seaside Hill (and by proxy, Ocean Palace) in more recent Sonic titles comes across as a bit odd. It has this weird form of Wolverine Publicity going for it: Seaside Hill had three courses in the first All-Stars Racing and another in Transformed, not to mention a winter variant was featured in Mario & Sonic at the Olympic Winter Games and Seaside Hill was used as the representative for its game in Sonic Generations. Granted, it has yet to be milked to death in the same way Green Hill Zone has, but it runs the risk of doing so, especially since Seaside Hill is the GHZ throwback level of Heroes (mixed in with Palmtree Panic, but the inspiration should be readily apparent). Even if every track has to feature at least two of the three vehicle types, there are certainly more interesting choices across the board: Angel Island Zone, Launch Base Zone, Flying Battery Zone, Lava Reef Zone, Sky Deck, Metal Harbor, Grand Metropolis, Egg Fleet, Cool Edge, Dragon Road, Aquarium Park... The list goes on and on, and that's not even getting into the handheld titles or other spin-offs. Sega and Sumo had to have realized this if they were willing to include Sky Sanctuary and Starlight Carnival in Transformed.
Nintendo will eventually get a guest racer, but it won't be Mario.The Mario & Sonic at the Olympic Games titles are the reason Mario didn't make it into Sonic & Sega All-Stars Racing in spite of the game being a perfect fit for the Mario Kart alum. However, he's not the only Nintendo character (first or second-party) to have their own racing game. As sorely tempting as it'd to be to say, "Put Captain Falcon in the game!" him riding in the Blue Falcon would be akin to Sonic actually getting out of his car on the land-based tracks and running on foot unless you shoved him in a go-kart version of the F-Zero machine (a la MKWii) and gave it the ability to transform (which would be amusing to see in action). Diddy had his own racing game with three distinct vehicle types (each corresponding to the types found Transformed quite well) and Wario has his own muscle car (best seen in Wario Land 4 and Double Dash!!), making them both feasible options. Personally, I'd bank on Kirby. I'd assume that the Warp Star and most of the Air Ride Machines from Kirby Air Ride would be relegated to All-Star Move status if implemented, but the problem of the Wheelie Bike being only a land vehicle could be circumvented by sticking Kirby on a metallic-looking Air Ride Machine (particularly the Dragoon or Hydra) or in the Starship/Star Chariot/Star Shooter, and then giving that vehicle transforming abilities (you could even make the car mode a mechanized Wheelie Bike). In the case of the Dragoon/Hydra, you'd even get "Legendary Air Ride Machine" as the All-Star Move theme. Even better, Lycett said that if they had asked Nintendo for an exclusive character in the Wii U version, their pick would've been Kirby.
They'll be a Super Smash Bros.-like game eventuallySega has more than enough characters to make one. They already have racing and tennis games, a fighter won't be absurd. Sony made PlayStation All-Stars Battle Royale so it's not like it'd be seen as too ripoff-ish.