we recently cloned an email, created a new email (draft) - but when the email was launched, it didn't send the new edited draft. Is this because the new draft was not approved?
Sanford's right - this is why we have an Approval stated. Marketo will automatically save any changes you make in the draft form, but it won't accept those changes as "live" until the asset has been approved.
Before a send, it always pays to run a test send of the approved asset to double check you've got the right content.