I keep reading words like "forced" in regards to consumer adoption of Blu-ray and "replace" in regards to some people's current DVD library. I must have missed something, because I wasn't aware that DVD was a dead format. I also didn't realize that DVDs you've already purchased somehow stopped working now that Blu-ray is here, and that you have to replace your entire library with Blu-ray versions.
The DVD format has many years of life left in it. The DVDs you own now will continue to provide the same experience they always have, and it's pretty much a sure thing that any Blu-ray player released in the future will be be able to play DVDs, so you're covered on the hardware front. When your DVD player finally dies, buy a Blu-ray player cheap and continue to enjoy your DVD library, while buying future titles on Blu-ray.
The way some of you talk, you'd think there was a gun pointed at you. So much unnecessary angst over a home video format.