Very cool news here. Not only is the PS4 getting Kratos as a character in Shovel Knight but yes the Battletoads are in the Xbox One version. Here is Yacht Club Games post on their blog:

"We’re incredibly excited to reveal that Shovel Knight will be coming to Xbox One in April! So many players have been knocking down our door, asking for us to bring the game to Xbox One… we’re so happy to be working with Microsoft to give everyone a chance to play Shovel Knight!

But we’re collaborating with more than just Microsoft! We’ve had the Rare privilege of working with one of the most celebrated studios in gaming. Take a look at the incredible collaboration with Microsoft to ensure the Xbox One version packs a lot of extra punch (above).
That’s right! The Battletoads, who debuted on the NES in 1991, are going to be returning in the Xbox One version of Shovel Knight! It has been so much fun to bring the radical attitude and gameplay of the NES classic to the Shovel Knight world. If you have ever played Battletoads– we’re pretty sure their extreme adventures left an impression!
Needless to say, the encounter with the Battletoads will be a blast…feel free to pore over these teasers and speculate. Just don’t call Gamestop and ask for Battletoads in Shovel Knight… it’s not available just yet!"
And for those who didn't see our post back at E3 about the PS4 version here is a LINK and a picture!