Is it all new releases they are delaying 28 days, or is it just Warner Brothers?
I don't even want to have the Blu-Rays unless they are really good, and I don't know that until I see them. If I buy a movie it is after I have seen it through Netflix. When I put a movie on Netflix, it is generally based on a recommendation. So if someone recommends me a movie, and I can't add it on netflix for 28 days, I'll forget and that will decrease my (already low) chances of buying it.
I love movies, but I don't really like owning them unless they are a reference disc or have a high replay value - and that's rare. To me, having a shelf full of blu-rays has no appeal to me. Expensive, takes up space, and most of the movies you'll never watch again.