I finally saw Forks Over Knives on Netflix this weekend & I have to say, if you haven't seen it see it!
I also happened to watch The Gerson Miracle (available free on Hulu) which incorporated juicing into a raw/whole food diet but essentially said the same thing. Plant based diets have a huge positive impact on your health.
Though I've been a vegetarian for nearly my entire life I am one of the few people for which giving up dairy has a negative effect, I'm tired and cranky & generally don't feel well due to a B12 deficiency. You can buy vegan supplement, but they're expensive and I prefer to eat my nutrients, not swallow them in pill form.
What I have decided to do is adopt a partially-vegan lifestyle. Which means I'm going to have a piece of cheese if I start feeling sluggish, but only hormone/additive free organic raw cheese (so I won't be able to afford much anyhow!)
The documentary showed a correlation between cancer & processed dairy & raw dairy (very difficult to get in the US sadly) did not show an increased risk for becoming ill.
I'll check back in in a few weeks to let you guys know how I feel.