The people floating this DVD -> Tape upgrade theory (oh, how wonderful, it looks better, no rewind, etc) forget LaserDisc! I mean jesus christ, am I the only person who owned a LaserDisc, had a collection of LaserDisc movies, rented LaserDisc, etc? And before you start complaining about form factor, at the same VHS was out, Betamax was smaller, superior quality, and people were still buying music on huge LP albums. The disc-flipping stuff is hardly what offed it, cost and content is what more or less killed it. (at one point, 10% of Japanese households had LD)
What killed VHS eventually was the studios delaying and removing content. I know people who only a few years ago still used VHS, especially older people. My mother was simply forced to DVD.
VCRs have one KILLER feature that during the 80s and 90s, people still relied on and that's RECORDING (most people are not sophisticated enough to rip/burn DVDs, and DVD copiers have no where near the bootleg penetration that VHS had). Who here didn't own two VCRs, and use them to record rented movies? I had a collection of hundreds of VHSes, all copied. I used to record entire seasons of TV in the age prior to PVRs on VHS. I had every Dr Who, every Star Trek, every RoboTech, Voltron, Transformers, etc
There are two simple reasons why DVD is going to die: #1, the studios are going to kill it. They have vast libraries, and need to resell them to a new generation. They also want better DRM. #2 BD Recording (remember, the format was invented for optical recording) will make a comeback, especially in PVRs and combo-PVRs.
I'll add a third. Every new PC manufacturer and every new optical standalone player manufactured will be BD, so that even if people buy them just to use for DVD software, eventually they will start buying BDs.
I find it hilarious how people who originally supported HD-DVD have now switched arguments after they lost. On AVS forums, it's now either "no one wants HDM" or "Digital downloads are going to win." Ungraceful losers I say.