Xbox Wireless Adapter adds 802.11g for $139 list: The news was accidentally leaked via an FCC filing days ago, but Microsoft now makes it formal. The release date is Oct. 5 for the product. The release foolishly says, gamers on Xbox Live can experience speeds of up to 54 Mbps. Most other Wi-Fi makers are careful to say the network operates at speeds that high, but actual throughput is substantially lower.