I agree this is a big problem and a huge turn off. It's getting harder to find original content on the "new" page.
@M@1neEvent had a great idea to start using a new tag #original-content
This will at least make it easier to spot the good content and raise it up. As for the spam, I think something needs to be done with the next HF. The way flagging is set up now doesn't really give you much incentive to downvote someone. It drains your voting power and gives you potential enemies who may or may not try to downvote you back (depending on your SP).