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.