I never played Dead or Alive Xtreme Beach Volleyball. Although volleyball happens to be one of my favorite sports (and back then, perhaps the only sport that I was fairly decent at), it didn't seem to me that DOAX was a good volleyball game to play. I imagine, that if I were to make a volleyball game, I'd probably make something like DOAX, but I would allow full control over the character selected and allow one to actually explore than island beyond a mere point-and-click interface. Maybe something akin to Wii Sports Resort, with a lot more full featured navigation and similar number of games players can play, in addition to being a good volleyball-sim.
Anyway, the video link I posted earlier is a preview of the gravure video that comes with special editions of Dead or Alive 5 Plus for the Vita. It isn't really a trailer for DOAX3, and as far as I know, they aren't working on that game.
I took a closer look at the magazine scan featuring the Zack Island stage and the new Paradise swimsuits. It appears that the stage is a lot larger than I thought. And it seems like it might have some danger zones, or some random elements that can affect a match there (there's a sequence with a fish, or a dolphin leaping through the air in the Kokoro vs. Lei-Fang picture). Several pictures showcasing the new swimsuits suggest that there are other areas to the stage not seen from the overhead view of Zack Island.
Still, it looks really nice. I think it'll end up being a fairly popular stage to play on if it appears to lack any major cliif hangers or danger zones.