This week's Steam marketing message reassures those purchasing The Orange Box over Steam will have access to the shooter bundle at the stroke of Midnight Pacific time on Wednesday:

We'll be unlocking The Orange Box products just after midnight Pacific time next week on the 10th of October. Lots of people have been having a lot of fun with the Team Fortress 2 beta, so we're looking forward to seeing what people think of Portal and Episode Two. The Orange Box will also be available at North American game retailers later on the 10th, for both PC and XBOX 360.