One of the reasons that I love Drupal 8 is the fact it is object orientated and uses the Dependency Injection pattern with a centralized service container. If you’re new to the concept, here’s some links for some fun reading.
When we talk about Drupal Commerce 2, the biggest we questions we get are not about features, but when you can start building with it. Well, the answer is and has been now! Drupal Commerce 2 has been in alpha and nearing beta. What does this mean? In alpha we might have some schema changes, requiring a reinstall of your site.
Plans were made back in December 2015 to put effort into the ability to support Migrate with Drupal Commerce to speed up adoption of Drupal Commerce 2.0. Commerce Migrate for Drupal 8 will provide migrations from Drupal Commerce 1.x, Ubercart for D6, and Ubercart for D7. Ideally, this module will also support other vendors, such as Magento and WooCommerce.
Drupal Commerce entities all make use of the "data" attribute. The data attribute is a blob that contain just about anything you would like - for example, Commerce Shipping utilizes this for shipping line items. Recently there was a StackExchange question on the documentation of this attribute.