take a look on http://www.wave-vs.net, it is more than a collaborative editor, is a Visual Studio Real-Time Collaboration Platform for team work Development supporting built-in Pair Programming.
•Implements Google Wave Protocol.
•Integrates with Major Source Control Version (SVN, TFS, VSS).
•Support Server Federation (you can setup multiple servers on different locations and make each one communicate to the others).
•Do not relay on Google infraestructure, you setup your own wave-vs.net Servers, you manage them and you choose how to handle all comunnications.
•All communications are TLS encrypted.
•Has embedded communications (IM, Conference Rooms...)
•With the Client is also install on your computer a wave-vs.net Personal Wave Server (PWS); You can use it to work together with other colleague, it is limited to up to two concurrent connections, if you need more than this, there is wave-vs.net Enteprise Server with unlimited number of connections, (the one supporting Server Federation).
it is on pre-release state, release version will be available around march 2010...
This release has built-in support for Vs2008, for Vs2010 will be released just when we get release version for Vs2010 and can check everything
For a complete list of features take a look on above link :) or go directly to Complete Feature List (http://www.wave-vs.net/product_features5.aspx)
If you want you can test pre-release :) just asking for a pre-release License Key, (follow instruction on email you receive with download instructions for wave-vs.net pre-release.
Enjoy!
Jesus.