Last month Microsoft launched Windows Embedded 7 Standard which included Media Center. One of the demo videos, available online shows Zune in the MC menus.
So it will be interesting to see if this was just a mockup, similiar to was done here or foretells things to come. We haven't discussed it much here, but I would imagine that the Zune team will have a fairly substantial update for the Zune desktop software to coincide with WP7 launch. Here are a few shots from an early build.
..besides this, I imagine internationalization is the primary focus to the fall release. If so, the bulk of the work will likely be hammering out licensing deals.