Even though it has barely put the finishing touches on its Windows XP Media Center Edition 2004 release, Microsoft is already forging ahead with the next two versions of its home-entertainment-hub product.

According to sources briefed by the company, the "Symphony," or Media Center 2005, release is expected to enter beta testing in the first quarter of next year. ("Harmony" was the code name for Windows Media Center 2004, which Microsoft unveiled in late September.) Based on past shipping history, Microsoft will likely release the 2005 version at the end of calendar 2004.