I have bought a few Blu-Rays that offered limited improvement over upscaled DVD, but they are in the minority. Realize that 1920x1080 pixels of data mastered from a degraded source (old film transfer, etc.) is just going to be 1920x1080 pixels of very nicely replicated film flaws. Poorly compressed/mastered video similarly offers little improvement as well. Some HD-DVDs seem to have this problem, likely due to the lower storage capacity (150 minutes of HD video will have to be compressed further to fit within 30GB than 50GB).
Compare clean digital source to Blu-Ray transfer (pixar movies, any CGI movie, or film shot with a digital camera) and the result is typically flawless. Watch the same film on DVD upscaled and if you can't notice the ridiculous difference in quality, your eyesight is either failing, or you really don't want to see the difference to justify the additional cost.







