I have a website that has grown very large and has a ton of inbound traffic from search engines (1.8M uniques per month). The problem I am facing is that there is so much content now, I believe that creating a new site on a new domain and moving some of the content to the new domain will improve ad targeting and the content overall. My question is about http redirects and their impact on search engines, specifically google.

If I create a new domain called xyz.com and redirect pages from the original domain named abc.com, what will happen to the links? The content will be pretty much the same from abc.com to xyz.com, and even improved. An example would be:

All requests to [abc.com...] will be redirected to [xyz.com...]

Will this eventually change the links within google from abc.com to xyz.com? Should I use an http 301? Has anyone done anything like this before? Will this negatively impact pagerank?

I appreciate any and all help.