Kudos to Haloplayers, who report that Halo has made the cover of the July 2000 issue of PCGamer UK, and that another preview of the game is contained within. The details are in the issue summary, along with a small version of the cover, showing the new marine in action.
And of course, a tastefully mounted slice of my eternal soul to the first fellow to send in a transcribed version of this article (or, just as good, the highlights from it) when it hits the shelves on July 6th. £7.99 per issue is a bit much for this hombre, though I'm sorely tempted with PCGUK's recent Halo coverage.
Update: Jenkz pointed out that this is actually the issue that came out on June 7th (damned numeric dating), and that the material within has already made it's rounds. So no soul for you! Grumble...