The quoteback project is a step in the right direction. It's a component you can use to display quotes from other websites in a standard format.
From what I can tell, the text isn't actually transcluded though. It's basically a fancy wrapper for a blockquote
element that adds an a
tag to it. You copy the text over to your page and your copy remains separate from the original.
There's also no way to see a page's backlinks.