Microsoft's (NASDAQ:MSFT) Halo 3 has officially arrived. What will it mean for Microsoft investors? What will it mean for video-game makers such as Activision (NASDAQ:ATVI), Electronic Arts (NASDAQ:ERTS), and Take-Two (NASDAQ:TTWO)? Will there be a halo effect for retailers such as GameStop (NYSE:GME), Wal-Mart (NYSE:WMT), and Target (NYSE:TGT)? In this installment of "Fool Video," Managing Editor LouAnn DiCosmo talks Halo with Halo-playing Motley Fool analyst Seth Jayson.