Before looking up the trademarks, I would've said I'm leaning towards Z coming soon, but those logos look great and Gen VII could indeed be around the corner. Here comes a falcon Pokémon based on Ra (sun) and Khonsu (moon), and Amun (a fusion for Amun-Ra, perhaps?) or Horus (sky) as the third version Pokémon. Just a little Egyptian mythology if they go that route.
Or, as crazy as this sounds, maybe we're getting more of Gen VI, with a few new Pokémon and Mega Evolutions (heh, Mega Heliolisk, Mega Sunflora, Mega Solrock; and Mega Clefable, Mega Delcatty, Mega Lunatone
). That would be something.
Also, abbreviating Pokémon Sun and Moon to Pokémon SM will make it sound like adult-entertainment parody, or like it's a service mark.