In the new Google Talk friends list, a voice or video chat button will appear next to your contacts when they are available to voice chat or video chat. If you receive texts from the person you're talking with, they will be overlaid on your phone's screen so you can read them without having to leave the video, though we're not sure why someone would want to text you while they're chatting with you in real-time. More importantly, if you need to check something on your phone, the video will pause automatically while you navigate to Android's home screen or to another app. The audio will, however, keep going even though the video is paused.
Google says it plans to roll out Google Talk with video and voice chat to Nexus S devices in the next few weeks as part of the Android 2.3.4 over-the-air update. The company did not give a release date for Android 2.3+ devices. It's worth noting that Google Chat for Android 3.0 (codenamed Honeycomb) already includes video and voice chat - Google is merely bringing Android 2.3+ up to speed.