BluRay will slowly filter in as people replace DVD players but only if the costs fall to a level where people decide it’s worth it.
The problem is that Hi-Def junk is still junk. DVD resolution is just fine for all of the film classics (and classic TV) that folks really want to own. Beyond that, the real difference between upscaled DVD (which all current DVD players do) and BluRay is marginal. And then there’s the “benefit” of BluRay’s DRM features (remember, HD video was never about delivering a better product to the viewer, but all about closing DRM holes in the DVD format).
Bottom line: Movies/Programming which isn’t worth watching isn’t worth buying in any format.