I am still not really convinced that it is possible to integrate handcoded schemas for a wide range of use cases into search results in a meaningful way.
The solution Google proposes here will also restrain the content of websites in a lot of ways if it becomes widely adopted. Look at the recipes-example, it defines markup for including nutrition information for recipes:
"Can contain the following child elements: servingSize, calories, fat, saturatedFat, unsaturatedFat, carbohydrates, sugar, fiber, protein, cholesterol"
Every company that serves recipes on the web and decides not to offer this information because it deems other properties of recipes more important is now at a disadvantage. Google will show more information about the recipes of their competitors and presumably also rank them higher because they have included 'valuable' markup information in their recipe.
This approach favors shallow information ressources over complex ones as the former can be more easily parsed by metadata-crawlers.