An update is in the works for the Windows Phone app, LazyTube. Version 2.4 has been submitted to the Marketplace for certification and should be available in the next few days.
v2.4 brings Live Tile support to the YouTube application that will alert you on updates to your YouTube subscriptions. The Tile will keep it's chameleon traits, mimicking your Windows Phone theme color.
LazyTube is a great application for your Windows Phone if you are a YouTube fanatic. Having a Live Tile to show you when new videos are added to your subscriptions will only add to an already fine app.
There is a free trial available for LazyTube with the full version running $.99. You can download it here (opens Zune) at the Marketplace.