While Microsoft has released its own YouTube client for Windows Phone 7, this client leaves mixed feelings. While videos are nicely integrated into the Music & Videos hub for playback, the client itself isn't anything more than just a link to the mobile version of YouTube. However, now HTC has picked-up this topic and has recently launched its very own YouTube Mobile client for Windows Phone 7. It allows to browse, search and watch videos within the client, get related video recommendations, as well as it allows to share video links via E-Mail.
HTC's YouTube client is now available free of charge from the Marketplace. However, while it's only available for HTC devices from the Music & Video category, it's not available from the HTC Apps section.
Cheers ~ Arne