I don't know if the demo itself gives you a Shiny Sylveon or whoever it is playing got really lucky.

Hoenn is finally confirmed for Nintendo 3DS, with Omega Ruby and Alpha Sapphire!

Costing 22,800¥, these consoles come with Pokémon X or Pokémon Y pre-installed. The blue Pokémon 3DS XL will be released all around Japan, while the gold one will be released only within Pokémon Centers. It is currently unclear if one, or both, will make it outside of Japan.

This doesn't apply to everyone, but it does apply to a lot of people I've seen who have heard the news of X and Y.