As I continue on my quest to get more information about IronRuby, I figured it was worth figuring out what needs to happen in order to contribute code back into the project.  The source code for IronRuby is synced with RubyForge every so often, and patches to the source code can be submitted on the RubyForge project here.  Before making any contributions to IronRuby a contributor agreement must be electronically signed.  John Lam's post to the IronRuby mailing list can be found here, and the actual agreement is available at: http://www.ironruby.net/contributor.pdf

The agreement appears to be pretty staight forward, the main point worth attention is that you grant Microsoft all rights to the contribution.

For good and valuable consideration (including without limitation the opportunity to contribute to the Project), receipt and sufficiency of which is hereby acknowledged, Assignor hereby assigns and agrees to assign to Microsoft its entire right, title,
and interest (including all intellectual property rights) in the Contributions.

Microsoft then licenses the contribution back to you to do with it as you wish.

Microsoft grants You a non-exclusive license under the rights assigned to Microsoft in Section 3 to use, reproduce, modify, license or otherwise distribute, and exploit the Contribution as You see fit.

If you're interested in contributing you need to send an email to ssiadmin at microsoft.com requesting to be added as a contributor to the IronRuby project.  I sent an email this morning so I'm not sure what happens next, but I'm assuming the electronic signing of the contributor agreement will be the next step.