HTC have taken it on themselves to release a YouTube app for their Windows Phone 7 Devices. It’s a horrible fact that Microsoft didn’t bother to include a YouTube app, amongst many other features, in Windows Phone 7. Call it version 1.0 or whatever you like, but even iPhone had it since version 1.0
Anyhow, the app is available for free in Zune Marketplace and lets you browse, search and watch videos from YouTube without having to launch Internet Explorer.