I'm completely content with my DVDs, and have yet to actually purchase a Blu-Ray for my own collection. It's so uncommon for me to notice any difference, that I feel I am Blu-Ray impaired.
@lyfling I feel similarly. I'm only really tempted to get Blu-Ray when it comes to Pixar, or things like that. They put SO much detail into their creations, the Blu-Ray is really stunning. But of course it all depends on your TV, and things like that... and yeah, really overall... is it worth it? Or do we really notice if it's missing? Meh.