Content Sharing - SEO Implications

I've been working with a client (let's call them wizbang.com) on some pretty straight forward optimization work in order to bring up the relevance of the content on their site.

To put this into context, this particular client has over 200,000 pages of content already indexed on Google (and climbing) and it's not a forum.

They're in the process of licensing out their content, and I've been tasked with determining the SEO implications of it from the perspective of their clients.

We all recognize that if it looks like simple content replication, from the engines' perspective it may harm us, but what we're trying to figure out is how to have it HELP their clients.

So, for example - say they have a client (zipperlock.com) that wants to license their content. We'd like to set it up so that they can do wizbang.zipperlock.com to access the content, and have the pages of content count towards zipperlock's page count and SEO work.

We've recognized that we need to
- address common title & meta information to maintain apparent consitency
- different IP address issues (perhaps we run a proxy on zipperlock.com to redirect the subdomain?)
- internal linking strategies, so that the links from wizbang.zipperlock.com support zipperlock.com, not wizbang.com
- content duplication issues (would Google frown upon two sites that have the same articles?)

Any thoughts/comments/insight would be appreciated. I'm not 100% certain about what would be required technically or what the potential pitfalls may be.

As a note the flip-side of this i that if we went with the client.contentprovider.com example - and made the site look a lot like the client's site, we'd suddnely be adding well over 200,000 pages that link to the client's site - which may help their SEO efforts MORE than just giving them 200,000 pages of content.

Thouhts?

Good God. I'll buy 200,000 pages from you haha. I'm still trying to figure out what your situation is here. If you have 200,000 pages of your own, then why copy them over to a subdomain and keep the originals? Even if you're licensing them to somebody, I can't seem to understand why someone would go to your client's site instead of yours if it's the same content.