WD released new WD TV player called WD TV Live Plus. There are only three visible differences with older Live version and that is unlimited membership to Netflix, support for Real media files and DVD menu. So I guess it is not worth an upgrade, at least for me.
From the site:
Play media from your home network and the Internet on your big screen TV. Plus, enjoy access to your Netflix unlimited membership and other premium content. Don’t confine your movies, music, and photos to your small computer screen. Experience them as big as life on your TV in Full-HD 1080p with WD TV Live Plus HD media player.