I don't know if there are plans for this yet, but it would be extremely useful to allow customers to pre-order products with Commerce.

If products had a release date field then this could be checked when on the product page and the first step would be to change the "add to cart" to "pre-order this product" (or similar).

Then ideally from a customer perspective, it would be better to still have the products all go to a single basket but at checkout, ask the customer if they want to ship as one order when pre-order items are released or split the order and ship the stocked items first and the pre-ordered items at a later date when available.

Also from a store owner point of view, keeping track of pre-orders is a great way of getting people to purchase products early, rather than lose out to a rival business and also to make far better judgement calls on how many units to order of a product.

Thanks