Another mention of the Halo original with XBL:
"This speculation gains credibility from the appearance of a Prima Official Strategy Guide for Halo Deluxe Edition on the publishing company's website, with a launch date of December 2003 - an embarrassing mistake by Prima if they turn out to have blown Microsoft's surprise, but surely a pointer that MS has something Halo-related in the works."
http://www.eurogamer.net/article.php?article_id=53739