Spec scripts vs Shooting scripts

It really seems like 99% of the major-studio produced scripts that you can find online are shooting scripts rather than spec scripts. What's that all about?

Meatball Heroes

If you're like me you've been watching Heroes since the beginning and have no idea why. I think I'm finally ready to give up on it. It's about 1000 times better in theory than it is in practice. It's not just that the storylines are either predictable or ridiculous, with completely unnecessary foreshadowing and time travel, etc. It's that the dialogue is unbearable. And it's not just that the delivery is poor (sorry Milo and Hayden, but you need help), the writing is really really bad. I will post examples when I have time.

Slumdog Millionaire (spoiler alert, sort of)

I saw Slumdog Millionaire a couple months ago and I still can't decide what I think of it. I was a little annoyed by the music at times, but I enjoyed the scenery and poverty-specific themes that are often hard to find in major American cinema. Overall I would recommend the film to most people, but I feel like it's vey commercial in an interesting way... While the film is somewhat emotional, it lacks a certain soul, possibly because of the constant time shifts, but also maybe because for all its originality it remains formulaic in the end.