There was a recent post on the Shopify eCommerce forums where someone asked how to change the sort order of products in the Admin (not the storefront). I can actually see the use case for this but thankfully a simple url change can make it happen.
The Shopify Product API contains an order property to let you sort the data. Since the Admin uses the API we can use that same property and get the same ordered result. This means instead of a url like this:
You would use one like this:
Change the asc to desc if you want to sort in the other direction for the created at date.