I grew up in the 1950s and early 1960s, when university courses were being offered on TV and a lot of people thought television (along with "teaching machines") would play a major role in education. The predictions didn't come true. For that matter, it was only a few years ago that CD-ROMs were being hyped for their multimedia capabilities. The multimedia CD-ROM market never really took off, partly because of the Internet but also because multimedia CD-ROMs weren't a very efficient way to deliver information.
On the Web, multimedia is useful as a supplement to text, but it's seldom a useful replacement for text. Take a travel site on London: Travelers might enjoy watching video of the Changing of the Guard at Buckingham Palace and a boat tour of the Thames, but when they're looking for hotel recommendations or museum opening hours, it's much more efficient for them to read text--whether that text is on a Web page, in a guidebook, or in a magazine article. Five years from now, video may be delivered more smoothly and at higher resolution, but that won't change the fact that a video isn't the best way to learn where one can find a nice double room for XXX pounds a night within walking distance of Harrods.
By the way, I think it's important that people distinguish between "the Internet" and "the Web." The Internet is a means of delivery; the Web is a specific medium. To put it another way, the Internet is like the Post Office, while the Web is like the magazine that arrives in your mailbox. Of course, the Web is often used as a front end to the Internet; an example would be a Web link that starts a file download. So an outfit like Netflix or Blockbuster might well deliver movies via the Internet in the future, using its Web site as the ordering mechanism. But that doesn't mean movies will be taking over the Web--it just means the Web will be used as a way for people to look up, order, and request movies, just as it's a way for people to order airline tickets or book hotel rooms now.