Google has just released a new version of YouTube application for Android. Some of the new features are:
In-page playback: you can read the video description, browse related, rate or flag videos without having to interrupt video playback.
Posting comments: you can post a comment while the video is playing, just like on the desktop website.
Subscription updates: we've made it easier to access new videos from your subscriptions. If you are signed into your account, you will see all your subscription updates right on the home screen of the app.
New full-screen UI: To enter full-screen mode simply rotate the phone. The new player controls make it easier to seek within the video, and you can pause or resume the playback by just tapping on the screen.
This new version works on Froyo and above and applies to 43% of Android users that have it. A good move from Google to update apps regardless of the system updates.