As the iPod rendered CD collections obsolete virtually overnight (a thousand songs in your pocket was the first slogan), the iPad will do the same for all the rest of the media.
The only gaffe Apple made was initially releasing the product with no 3G. They should have waited until 3G was ready as the device is essentially crippled where there is no Wi-Fi. People that rushed to buy one first will be disappointed later when people who waited are able to download media from virtually anywhere.
If the media downloads are going to be proprietary from Apple then this thing only further enslaves users to Apple it doesn't free them up.
What computer attached to the internet doesn't have that?
My daughter's netbook from Dell does that, and at about half the price.