Code review addin for Visual Studio

This isn't so much as a question, as an idea which I think would be helpful. I decided to post it here to get feedback on the idea. I'm not sure if this isn't exactly the right place to post it, but I wanted to see what you guys think.

My idea is to create an code checkin policy which displays a diff of each modified file. To be able to check it in, another programmer has to 'sign off' on it; this is done via the other programmer using either Active Directory authentication, or just putting in a username and password from a random database. Obviously, a user wouldn't be able to sign off on his own code.

Ideally, it could be mixed with the sample from Microsoft which applies a checkin policy only to specific files, or to ignore small changes, and so on.

Or, is there already such a third-party policy?

From stackoverflow TraumaPony

• I'm not sure about the policy location storage or whether a "user" has control over the "admin" or project managers' code settings, but DevPartner Studio is one of the most complete code review and analysis tools I have come across. It might be worth a try.

  http://www.compuware.com/products/devpartner/studio.htm

  From $pageUsers[$post.author].name

• Have you evaluated TeamReview? It's not exactly what you're asking for but it's an Add-in that facilitates a rich code review experience in the IDE. Because it uses Team System work items the "approval" aspect your asking for is the completion of those items. Regular Team System reports and queries can be used to make sure the work is "signed off."

  Also - you might consider using the Source Control Annotate feature of Visual Studio Team System, Attrice's Code Review Side Kick, as well as the Code Review Workflow project on code plex

  TraumaPony : I'm not looking for such a thing; I was wondering if people thought it was a good idea.
  From JB Brown