According to the official news of Joomla developer network, the JoomlaCode.org, a resource for the Joomla centered projects, would shut the service. The Joomla! developers have decided to do so as they received the intimation from Google webmaster tool about the spamming of blackhat content and links. Though, merely this problem is not the reason for shutting down the service, additional reason is also there.

For Not Compromising the Users’ Security is the foremost reason

They will have to take this step for protecting their users against security vulnerability, although they have said that, “No confidential user information was obtained, and quality hosted projects are not compromised.” The suspect is a sneaky SEO who have used any blackhat technique to generate good traffic for its websites, indulged in selling illegal pharmaceuticals, and this lead to the demolition.
The users don’t need to worry too much about this spam attack on JoomalCode.org since the folks have been working for cleaning the SPAM.

They have also accounted the additional reason

The additional reason that has been given by them is inability to run this platform due to lack of resources. Their long term software provider, GForce will not support them longer; therefore this service is being moved to the end. The developers have shown their inability to keep supporting JoomlaCode.org for long term, backed by the reason that they have been facing the lack of resources.
The project owners can move (host) their projects to the other repository hosting platforms. Indeed, for their convenience, Joomla! has made an action plan.

The Action Plan for Closing the Service

The Joomla! developers have made the strategy to shut down the service. According to that the projects owners will be informed via Email and an additional communication channel will be created with them. Besides, the websites’ home page will also be updated before closing. Apart from this, all the Joomla release packages and accredited translation packages will be copied to a new hosting platform along with the backup of download statistics. Specially, for the GitHub hosted downloads, analytics tools would be developed.

Source: http://developer.joomla.org/news.html