For those in the preview it looks like you will still get beta versions of the apps even after the update goes live.
As is the case, what's more interesting are the apps that won't be making launch week. YouTube, Verizon FiOS TV, Vevo, UFC, Crackle, and 22 more are all listed under "later in December." Dailymotion is listed here, too, even though it's been working great in our Xbox Live dashboard preview build; Microsoft told us, as part of the beta program, we would continue to have access to some apps not yet released to the general public. That applies to SyFy, too, which is in the current preview build but not on the latest list that Microsoft sent out this evening.