Though the full game's not expected to be ready until at least September, Microsoft has already lifted the curtain on two special editions for Halo: Reach, the first-person action title they are calling "the biggest game of 2010."

With a beta trial of Halo: Reach being made available to any and all Xbox 360 users who own the previous game in the series - the reduced-price Halo 3: ODST, Microsoft has certainly dropped the reveal at an optimal time, targeting those players who find their enthusiasm for the franchise skyrocketing following feedback from the open beta.

As well as a standard retail copy, expected to sell for $59.99 / €64.95, there is a Limited Edition ($79.99 / €79.99) whose wider box houses a journal purported to have been written and illustrated by a Dr Catherine Halsey, a scientist from the futuristic series who was instrumental in setting up the super-soldier program that spawned Halo's powerful Spartan warriors. There's also going to be a sew-on badge, a couple of Dr Halsey's personal effects, and a code allowing players to wear an exclusive uniform during multiplayer sessions.

The Legendary Edition has been given a heftier retail price of $149.99 / €129.99, and its crate-like packaging is large enough to swallow both the Limited Edition and a collector's statue showing Noble Team, one of the the five-person assault squads used by the United Nations Space Command in the year 2552, and central to the Halo: Reach story.

With the special editions now revealed and retailers preparing to take pre-orders in advance of the Electronic Entertainment Expo in mid-June, the game's developers Bungie are thought to be preparing for a different sort of announcement at the conference.

Microsoft's press conference on June 13 has been earmarked as the day their Project Natal motion control system is revealed in further detail before its launch a few months afterwards, so fans are expecting the Xbox 360 Media Briefing on June 14 to contain big news about the Halo series, among other things.

Halo 3: ODST has already started climbing back up software sales charts in advance of Reach's worldwide beta commencing on May 3.