I have the new Island. Just took a 11hrs dragon from the den to the nest and got 3 marble parts.
It takes 100.000 coins and a marble key to expand the first square of land. I can buy one marble key for 10 gold. I'm currently using my Spell shop, so I haven't had the chance to see what has changed in there.
Next up is a 5hrs dragon, then I know more.