Once a pre-order has successfully completed remove it from the pre-order table. It is already listed in the normal orders table and it looks confusing when everything is duplicated in both tables.

Likewise for the use case of an existing pre-order that has not yet completed. It would be better if this wasn't displayed in the orders table as it is already listed in the pre-orders table.

For downloadable products it would be nice to have the download button in the options <td> of the orders table once it has successfully completed.

It would be good to be able to track the amount of pre-orders in the admin frontend too as you would track the total orders figures. I couldn't find a meta_key that gave me that data unless I'm missing something.