Microsoft accidentally uploaded the forthcoming Gears of War 2: All Fronts Collection to Xbox Live Marketplace late last week for half its planned cost.
"Earlier this morning, the Gears of War 2: All Fronts Collection Game Add-on was briefly made available on Xbox Live for 800 Microsoft Points," the company said in a statement about it (thanks Joystiq).
"The content has since been removed and will launch on Tuesday, July 28th worldwide as planned, together with the Dark Corners Game Add-on. Pricing will remain as originally intended (1600 and 1200 Microsoft Points for All Fronts Collection and Dark Corners, respectively).
"The small, lucky group of Xbox Live members who were able to download the content during the short window it was available will be able to retain the content for the price at which it was purchased as well as keep all related Achievements. There won't be any penalties for those who purchased this content early. Think of it as a lucky treat for those with quick reflexes!"
Or think of it as a massive cock-up, if you like.
Dark Corners is an expansion that consists of seven new multiplayer maps and a new campaign chapter called Road to Ruin, while All Fronts combines that with the existing Flashback, Combustible and Snowblind map packs.