Since Microsoft's official announcement in Billboard didn't tell us all that much new info, here's a little bit more on Zune's rumored capabilities from another tipster.
There's going to be an add-on game pad similar to the Sony Ericsson P800 Bluetooth game pad. However, this one is going to be magnetic (really?) so it can attach to the Zune. Isn't that bad for magnetic, hard-drive based storage? You'll be able to use this game pad for "classic gaming", probably somewhere around the mid-80s to early-90s, NES/SNES-level graphics.
They'll let you customize your own case when you buy the Zune, whose default case looks pretty much like the pictures we've been showing here. You can change the outside, add RAM (for gaming, or PDA features maybe?), reduce storage space, and change the colors of the finish.
And here's the "viral" site that Microsoft set up for Zune: Coming Zune [comingzune]