DVD technology is going through a rapid evolution, IMHO how fast the new technology gets accepted is another factor.
Many people have invested in high end DVD players because the picture is already outstanding, this won't be like going from VHS to DVD. Price and compatability to existing systems will also be a big factor. I'll give myself a couple years before I make a decision on going with the new stuff, I'll let HD DVD and Blu-ray battle it out in the meantime.
Good article here. Link

A computer once beat me at chess, but it was no match for me at kick boxing.