Heh, I guess you're one of the people who used the "Add a product" link in the store administration menu.

That got taken out because there was already a place to do that in the Create Content page. Since product classes became node types, that page became more important because it was the only way to create products of different classes. We figured it would be confusing if people made product classes, but then couldn't create them through the old "Add a product" link. This also makes it feel more like Drupal because that's where all the node types are created.

Sorry for the extra confusion.