I always thought that if they were gonna' end on a certain generation, it'd make most sense to end on Gen 6. Since, well, you are able to have a total of six Pokémon in your party and stuff.
Well, honestly I could probably do without RSE-remakes. Now a Colosseum/XD-ish game for WiiU, that's what I wish for.
Also, the theme for this generation is apparently DNA.