years ago someone (belkin or some other name brand manufacturer) came out with a device that allowed ipod to ipod transfers. apple lawyers swarmed down from the heavens and the device was wiped from the face of the earth. such devices do pop up now and then, typically from un-heard of manufacturers. these devices seem short lived.
apple has even come down on developers who have reverse engineered the ipod filesystems and databases to write applications to allow transfer out-of and in-to ipods and iphones. they've also made it difficult with various software methods as well.
it's pretty clear apple doesn't want non-apple-authorized devices poking around in iDevice file systems.
jobs has gone on record stating he has no love for DRM.. and he has no love for piracy. it took apple
years of fighting with the music industry to get them to agree to drop DRM, it will take many more to convince the publishing industry to do the same.
i am not saying all users are automatic pirates (i abhor the RIAA) but through their actions apple is pretty clear in not wanting the general public to easily copy music in and out of iDevices (or we'd have the drag and drop filesystem on the iPad many wish for).
i don't think, for an instant, apple couldn't create an ipod to ipad copy system if they wanted to. i could buy a 16G iPad for $499 and a 160G iPod Classic for $249 and have 176g on hand in two small devices and copy across media fairly quickly if apple wanted.
you're right. apple could try and lock it down my only allowing devices that synced to the same computer. but it would cause hassles with consumers as well. mom and dad wanting to know why little johnny's ipod at school can't come home and upload pictures into their new ipad (because he syncs it at school). i'm sure there are other reasons. apple chooses the path of least hassles and just doesn't come up with such a system.
you'll always find people willing to pay more money for the higher memory system anyway. personally i'd rather have 64G on hand than to deal with a stack of SD cards. 8G cards are fairly common these days, but i don't want to be carrying around a 16G iPad and 6 cards to make up for the 64G. and those 8G cards aren't cheap either. looking at
supermediastore.com 8G cards range from $15 (on sale) to $25 depending on manufacturer and speed. say we go with the $20 cards, that's $120. Your $499 + $120 iPad just shot up to $620, not far off the mark from the $699 for the 64G iPad is it? You also don't have the hassle of dealing with 6 SD cards.