I don't know for certain, but the prevailing evidence suggests it wont happen:
1. They have not allowed it yet and people were pretty upset about it when WP8 came out. It probably takes ~zero effort to make it work
2. Not compatible with WinRT, would have to build a new program from scratch
3. There really aren't that many people who ever used it and know what is missing (Zune and WP7 were not popular, no offense). For WP to be sucessful it needs to take market share from Android and iOS, so Microsoft's target consumer is not going to miss Zune
4. Current program allows integration with iTunes, Windows Media Player and works fine in disc mode
5. If they commit to making Zune work for WP8, they will have to continue to support it, and that takes a lot more work than supporting a lightweight program like the WP8 syncing program they have now
6. Xbox Music Cloud Collection - while only for Windows 8/RT at the moment, everything is moving to the cloud which negates the need for an additional program to manage syncing
I just wouldn't count on ever seeing WP8 integration