CG Online has a short interview with Jason Jones, original cofounder of Bungie Software Products Corporation subsequently sold to Microsoft and transmogrified into Bungie Studios, developers of Halo for the Xbox. They asked point blank if Halo would still come to the PC, to which Jones replied point blank, yes .

The timetable is still up in the air. Jones points out that Bungie employees were given vacation after Xbox Halo was completed. In addition, CG Online asked:

Is Halo a better game for having been made into a showcase title for the Xbox? What have you been able to do, technically and in terms of production value, that PC gamers will see when the game is released, but wouldn't have seen if the game had just remained a PC/Mac game forever?

Well obviously we have been able to focus on two major areas for the Xbox version.
1. Single player story
2. Graphical/Audio fidelity

The Xbox really frees Bungie up to turn on all the bells and whistles. Bungie no longer had to worry about making it optimized for hundreds of different computer configurations or a low the minimum spec. We only had one minimum spec and one configuration which allowed the team to max out all the settings. Things like Dolby Digital 5.1 surround sound, bump mapping, pixel reflection or volumetric lighting will just blow players away. These processes are expensive and require tremendous horse-power that is standard on the Xbox.

They also asked about Bungie's plans for the Xbox's online capabilities, to which Jones replied that details are yet to come.

Thanks to Maarten Goldstein at Shacknews for the heads-up.