May 01, 2009
One of our team members has built a pretty cool sample UI that allows syncing of multiple web servers and also using file change notifications to trigger syncs. Take a look at the sample at http://blogs.iis.net/moshaikh/archive/2009/04/26/web-server-change-notification-or-web-server-compare-or-multi-server-sync-in-a-web-farm.aspx
BTW we do plan to add this functionality at some point into the Web Deployment Tool itself but it will likely be after version 1 releases.
Velocity is for session state management. MSDeploy is for syncing IIS Configuration information, content, databases, certificates etc and such changes and not for synchronizing the session states between live servers.