http://imgur.com/Wj3HH9E
Here is the tiny bit of code to do it:
Nop.Web.Controllers.ShoppingCartModel
Line 80 public string StockAvailability { get; set; }
Nop.Web.Controllers.ShoppingCartController
Line 461 StockAvailability = sci.Product.FormatStockMessage(_localizationService)
OrderSummary.cshtml
<div class="stocklevel">
<strong> @T("ShoppingCart.StockLevel"):</strong> @item.StockAvailability
</div>
And you need a value for "ShoppingCart.StockLevel" in language strings.
Nop Team, Please add this to the next release...
This is such an obvious need, it should have been there versions ago.