The online embarkation form will speed up your check in at the port. It is used to set up your onboard charge account. It also sets up your government identification requirements. You will still need to bring your identification documents and your charge card with you and present them at check in.
I find this a very positive thing. It does save time and makes the whole boarding process easier. It also gives you something to do while waiting for your cruise. <VBG>
Take care,
Mike