I use MyBrand, the service that allows me to map a domain I own to my feed. Do I need to change anything?
Yes. After transferring your account, you will be sent an email with instructions on how to change MyBrand. You can also get these instructions on the MyAccount page after the transfer. You will be required to change your DNS CNAME to the Google hosted domain service, the same service that handles custom domains for Google applications like Blogger and Google Apps for Your Domain. Please note that the CNAME will no longer be the same domain as the domain that serves feeds, but the service level and functionality will be identical.