You can pull information from
http://api.justin.tv/api/stream/list.json?channel=CHANNEL_NAME. Bitrate and uptime can be seen respectively at video_bitrate and up_time.
Please note that this endpoint has not yet been moved to kraken and is therefor subject to change without documentation. There is also no documentation on this endpoint since it is not on kraken.
Also note that this endpoint can also be served as xml instead of json by GETting from
http://api.justin.tv/api/stream/list.xml?channel=CHANNEL_NAME