You CANNOT clone on to one of the new MBPs. If you do you will still have to re-install SL to get all of the new drivers.
So your choice is to clone anyway and then perform a re-install using the provided new SL disc or you can just boot up to the new HD and then Migration Assistant your user back to it.
You will not be able to just clone and go. It fails on boot-up. If you do re-install over it after cloning, there is no worries, your user and settings will remain.