There's a ton of information about the Monthly Bundle here:
http://www.steamgifts.com/discussion...-poll-and-info
Including:
It will contain 6 games each month. All the games will be for Steam, but in the future, the bundle may include DRM-Free games or games for other platforms too. (via IGN)
• 1 hot title - Less than one year old.
• 1 highly-acclaimed title - Between one to two years old.
• 1-2 hit indie games.
• 1-2 hidden gems from developers.
And all games are separate keys and giftable.
