Basically summed it up in the title--if you create a new site that gets new content every day or two, but quickly thereafter other sites start to copy it as well (say a few days), will you be put in supplemental or will the copiers?
New site gets filtered. Some people complained that Wikipedia have stolen some content from their site and they went into dupe penalty filter.
Yes, this is becoming a slippery slope. I would recommend submitting an XML site map when your site updates to ensure your content is indexed first. Good luck.
Authority sites will win the batlle everytime. That's why it's important to SEO your site correctly (or have someone do it for you) so that it becomes an authority site as far as the SE's are concerned. Example: A new client came to us with a 3 month old travel related website. He was a prolific writer (articles) and was having difficulty getting content indexed and counted as belonging to him. Other larger travel sites were essentially stealing his work... using it as their own... and getting serp credit for it. We took his site and turned it into "THE" authority site for his travel niche. Now those other sites I spoke about earlier that were using his content... they are now providing him content.
The newest sites would get filtered -- the oldest sites would not. I know this is repeating and this post is old but the workaround is to make many scraped sites with duplicate content if you wanted to override another site OR take the site down altogether.