BluRay is doing very well. Check out the Home Theater Forum for a better overview of this media.
Home theater and stereo is a hobby for me. A lot of people enjoy golf, or boats, or gardening, or whatever the hobby, and spend a lot of money on those hobbies too. BluRay is simply the very best format for watching movies and home theater. I enjoy it and so do millions of others.
Deals are there too. Bought Groundhog Day, Tropic Thunder and the Peter Sellers classic "Being There" this week on BluRay for $19.99 each on Amazon.
But if you are not a fan, by all means continue to buy the standard definition DVDs and watch standard definition television. Don't spend the money on the great picture, the HDTV or HD cable service. SD might be best for some. But HD is best for others.