HD movies at 1080P? Don't count on it. Not enough bandwidth and no one is patient enough to download a 25+ GB file.
The playstation store has the video rental/digital movie purchase, but the HD content in the store is most likely 720P/1080i. As of this point, I have only seen certain video clips being downloadable in HD, but not full movies. I think those downloading pirated movies are satisfied with the DVD-quality downloads. You should be too.
If not, then go buy the BDs. They are getting cheaper and cheaper by the day. Amazon has the best prices. There truly is no substitute for HD video and HD sound. I love my PS3!