Just came across this cool software recently which may be of interest to you folks. It’s free to try for 30 days and minimal cost for an annual subscription.
Stream iTunes via DLNA to your WDTV SMP or pretty much any other device for that matter. No need for an Apple TV!!
Here’s the company blurb and a download link.
iHomeServer Is A Windows Application That Supercharges iTunes To Create A Better Media Server
iHomeServer adds features to iTunes that everybody can make use of, but particularly those who use iTunes as a media server within their home. It can start iTunes as a Windows Service so that iTunes is already running whilst adding brand new features such as advanced media watch folders, DVD ripping, video conversions to iTunes formats, metadata tagging for movies/television episodes, a web interface for streaming to all your favorite devices locally and on the Internet, publishing of iTunes to DLNA clients such as televisions and radios and much, much more
Download here: iHomeServer for iTunes