I just thought I would add some more requests as I find things while setting up my first cart and taking my first orders. This is an awesome cart, but I just thought I would throw this out:
People are really freaking out these days at shipping costs… It would nice if the weight of the shipment would show next to the rate at checkout, so people can at least understand why it is so expensive.
It would also be nice if the weight was shown on the “Order Info” and “Print Invoice” pages so that I can more easily prepare for packing when processing orders. This is also a big help to monitor your charges and make sure things are working properly. This would be a priority for me over showing it on the front end.
On the back end, I also would love it if when an order is processed with two different shippers (via addon), the charges show separate for each shipper (like the front end at checkout) rather than just a single total (the way it is now). and of course a separate weight for each shipper would be great too.
And while I am at it… weights should also show on the packing slip that I just know must be in the works 
I have a solution how to show weight in product description page if you like.