I have rented lots of Blu-rays and never found one that was upscaled from DVD to 1080p. Can you provide more details please since I am having a hard time believing that's true.
I did a quick Google search and found this article [1] ... I recall seeing a website that was listing Blu-ray titles with true-1080p but I can't find it right now. Cable does something similar by highly compressing HD content.
1. http://conversation.which.co.uk/technology/many-blu-rays-no-...