At long, long, long last Microsoft has released its promised DRM tool, allowing Xbox 360 owners to transfer licenses from one console to another. Meaning that Xbox 360 owners no longer have to be signed into Xbox Live to play titles they downloaded on a previous console.
Full instructions on how to utilize the tool can be found here, and it's a two-step process of transferring the licenses on Xbox.com, and then downloading them to the new Xbox 360.
Microsoft notes however that each owner can only transfer licenses this way once per year, and that previous transfers using the Migration cable will still require using this tool to take advantage of playing offline. Also, the tool works on anything except movies, which are no download-to-own at present.