ROMs chefs do not want to wait for that Google published in the coming weeks the code source of Android 4.0 (Ice Cream Sandwich). A few hours ago we met that they are beginning to use the new version of Android SDK to create ROM for the Nexus S, but will not be the only.
A group of chefs are also using the SDK to bring Ice Cream Sandwich to the Nexus One. As we can see in the video, who heads the news the result was not so bad, it is not completely fluid but to be a port fast and without optimizing for mobile is not nothing wrong.
This ROM is not available currently is not functional. Many applications and services Android 4.0 (Ice Cream Sandwich) are not in this ROM to not be available in the SDK, in the Android development kit are just basic applications which would have to wait for all the files in the Galaxy Nexus to seep.
To have an optimized version for the Nexus One We will have to wait for this available the source code of Android 4.0. Meanwhile it will be wait for Google to make public its source code and step confirm if finally the Nexus One are going to officially upgrade to this new version.