I didn't have much personal information in my Facebook profile, but I decided to delete it anyway. One thing I found is actually deleting an account is more involved than just deactivating it.
The procedure to deactivate your account is straightforward, but it just makes your account invisible to other users. All of your information stays with Facebook, it just stops others from routinely connecting with you. You can go back and reactivate the account at any time by just logging in to it.
Deletion is another step beyond that, and it is hidden elsewhere, seperate from the more visible deactivation option. You have to log into a seperate deletion web site, the option to delete the account is not available from within the normal Facebook interface. After you request deletion your account becomes deactivated for 14 days. If you access the account during that time, the deletion request is aborted and your information remains on Facebook's servers indefinitely.
I'm hoping deletion actually erases my information from Facebook's records. If it does, I may try it again in the future.