Well it looks like Microsoft is too busy working on the next Xbox Live to push out a Spring update this year.  But fear not there will be some changes released soon.  It seems that Microsoft will be releasing a new tool to help you get all your DRM content issues resolved.  So if you've either bought a new 360 or got a new one shipped back to your from their support, you will now be able to easily tie your new console to your previously downloaded content.

I tend to think it sucks there will not be any cool new features but I'm not surprised.  I suspect that Microsoft is already very busy working on the next Xbox Live.  I'm not sure if this means we will be getting a totally different dashboard for the Xbox 360 or if this will be for their next Xbox console.  With sales plateauing we could see a new Xbox in the works by end of next year.

Source:
joystiq - microsoft-no-spring-dashboard-update-this-year