If you signed up via the Xbox LIVE Dashboard to access the new Dashboard Beta, then I suggest you go turn on your console as Microsoft has started rolling out the download process to update your console.
If you were accepted into the Beta then you should by now have seen the BETA channel on the dashboard very recently which confirms your acceptance and requirements to remember that you are not permitted to blog or disclose any of its contents which could have bad consequences for your Xbox LIVE Account if discovered.
Sadly due to the NDA thisisxbox.com can not disclose its contents either, but you are bound to see leaked images and videos on Youtube – it happens every year without fail.
The beta sign-up process was only live on the dashboard for a limited time encouraging gamers to download an app which then uploaded console details to Microsoft for Beta inclusion. It is not known when the update will go live for everyone publicly, but those in the Beta should be able to download the contents and see all it’s new features (hopefully) as of right now! This is the update tipped to bridge the gap between the Xbox 360 and the Xbox One as well as swap MS Points for cash values.