Just in case you didn't notice this yet, Facebook has gone ahead and made the only visible email address on your timeline one that ends with @facebook.com . Since nobody in their right mind wants to use Facebook as an email client the people at Lifehack have put together a step by step guide to help you change it back (it's so easy that a KCMOSD grad can follow it).
This is just another reminder that nothing you have on Facebook, Twitter etc.. is your own property.