We allow guest checkouts in our multi-site/multi-store magento setup. When a guest customer checks out by credit card or invoice, when you visit the order in the adminhtml, the customer is identified as "Guest" but the entry is linked to a customer record. My guess is this "guest" customer record is not missing much more than a password. I can browse to the record from the customer grid.
However, when a guest customer checks out with Paypal (Express) this is not what happens. No customer record is created that I can find, and the word "Guest" on the adminhtml edit order page is not linked to an account.
This is very problematic for us. Anyone else have this issue, and is there a solution? Paypal checkouts must create a customer record regardless of whether the customer wants to "create an account" or not.