I occasionally download films, but I don't feel bad about it. My reasoning is this;
I always go to the cinema to see a film that I want to see. I never download it for first viewing. Heck, if I really like the film, I will still go to the cinema several times to see it, regardless of its availability as a download. (because cinema quality is better than low-res shaky-handheld-camera quality)
I download the movie if I think my dad would like it. He is unable to go to the cinema due to medical problems, so its not like the studio is losing money. He couldn't go and pay them anyway, so its no difference!
If a movie has managed to meet those two conditions, then there is no doubt it is already in my pre-order list for when it comes out on Blu-Ray. The studio still gets the same sale.
So I feel ok about downloading, because the studio still gets the same amount of money out of me as they would if I didn't download it. No-one is being ripped off. Everyone's happy.