The Jump scan shows the same dragon-riding artwork found on the teaser site, with two more characters than the site currently shows, revealing a party of four. Final Fantasy Gaiden: The Four Warriors of Light (not related to the Game Boy Final Fantasy Adventure, known in Japan as Seiken Densetsu: Final Fantasy Gaiden) is an original turn-based Final Fantasy RPG for DS, in the same style as the recent Final Fantasy DS remakes.
The scan refers to a "four-person party adventure," but we can't tell if that means multiplayer or if it's just a reference to parties controlled by a single player. According to IGN, the main character is a boy who must rescue a princess from a witch.
The battle system is a familiar turn-based, menu-driven system, with what appears to be the addition of a sort of action points: each character's status includes a certain number of yellow dots, and each action seems to have a dot next to it, indicating a cost. Final Fantasy Gaiden will be out this fall in Japan, and we wouldn't be too surprised to see it in North America the following summer for $40.