If I create an article directory and use some articles from ezinearticles and such, will I be subject to a google penalty? How does ezinearticles and others get away with it? I will include all author information, and sources.
No you won't. It's unfair to say "penalty" so much as it is you just don't get much effect. They may not rank your pages high, but you certainly won't be penalized. This is what we have come to know as the duplicate content filter. (Notice it isn't the "duplicate content penalizer") There is nothing to "get away" with as long as you include sources and information. If you really want to make a profit, I'd suggest that you add certain information to each post, and if rights permit I would edit paragraphs and make it a modified article. You might also try to show related articles to help get some more random content on the page. I have a custom-made spinner that takes an article I supply it and churns out 1,000+ variations that are not just readable, they are darn good articles. I would suggest you look into making something like that. There aren't any out on the current market that produce readable content, so don't waste your time looking for something that does the hard work for you. Changing the permalink that you use on the article is another good way to switch up content. Just because the title remains the same doesn't mean the permalink has to reflect the same naming convention. Good luck!
As a side note, I believe the success of big article distribution sites is that they don't take so serioursly what Google, as search engine does, but staying within Adsense TOS.
Staying within the adsense TOS? Ha! They rewrote the TOS! Being such a big network like they are, they get special privileges that us "normal folk" don't. In addition, they have a strict rule and guideline set for approving articles. I'm not surprised they got where they are just because of that simple fact.