The iPad does not automatically store Mail passwords in a retrievable format either. It does keep them, encrypted and obscured, but only so you don't have to re-enter them every time you get mail.
You can re-enter your mail password by going to Settings > Mail, Contacts, Calendars, selecting the account, tapping account, then, tapping the password field. Though if it is an iCloud account I recommend making changes under Settings > iCloud instead.
Anyway, there is still no way to retrieve the password.
There are several good to excellent secure password storage apps for the iPad, though none of them can integrate with Mail or Safari.
I like 1Password, not so much because it's better on the iPad than others as the integration and syncing it offers on all my other platforms. But it's not cheap.