Until 11:59 PM PST on February 7th, 2011, developers creating games for Xbox LIVE Indie Games can continue to submit their games made in XNA Game Studio 3.1 to peer review on App Hub.
Beginning at 12:00 AM PST on February 8th, 2011, only games made in XNA Game Studio 4.0 will be accepted to peer review; any games submitted that are made in XNA Game Studio 3.1 or any earlier version will not be accepted by the system.
When the restriction goes into effect, games already in the peer review process will not be affected. However, developers who expect to enter peer review near the deadline should use caution: the restriction applies to all games entering the peer review process – regardless of whether they are being submitted for the first time, resubmitted after failing peer review, or are updates to games already on Xbox LIVE Marketplace.
For instance – submitting an XNA Game Studio 3.1 game to peer review on 11:58 PM PST on February 7th is allowed, and while in peer review, the game will not be removed or changed in any way by the restriction. If the game passes peer review, it will enter Xbox LIVE Marketplace. If the game fails after the restriction is in effect, the developer must upgrade the title to XNA Game Studio 4.0 before resubmitting.
Submissions of updates to existing games in Xbox LIVE Marketplace are also subject to the restriction; any updates to existing games after the deadline must be made in XNA Game Studio 4.0, even if the existing game was made in XNA Game Studio 3.1.
If you are developing a game in XNA Game Studio 3.1, you will still be able to deploy and debug the game on your Xbox 360 console using XNA Game Studio Connect after the deadline, but you will be unable to submit it for playtest or peer review unless you upgrade the game project to XNA Game Studio 4.0.
If you have a XNA Game Studio 3.0 or 3.1 game currently on Xbox LIVE Indie Games, it will continue to work. This release does not affect the ability to purchase or play any game currently on Xbox LIVE Indie Games.