Straight from the anime news magazine Animedia.
An interview with Director Hosoda and Yoshida Shin of Series Direction confirms a few items.
The Speed Duel Format in the show will be similar to Riding Duels in 5D’s, but you can also move up and down, besides just going straight forward, using your D-Board. (It isn’t explained if it also uses the Speed Duel rules of 3 Monsters and 3 S/Ts).
As well, there will be Duels in which Duelists stand on the ground, that will be referred to as Master Duels, that will run on the normal rules.
Thanks to DMC344 from Neo Ark Cradle and Eva for help with this.