Blu-Ray will never take off as long as new prices are $30 and 'sale' prices are $20.
Especially when they're not worth it if you don't have a 42" or bigger TV.
I have around 20 blue rays and except for buying the Dark Knight when it first came out I’ve never paid more than $16 on any of them.
I have a larger set now but even when I had a 32inch I could still see a definite difference in quality. I suppose it really depends on how far away you sit though. HDTVs are made for closer viewing than traditional sets.