No, that really isn't a dumb question. It's an issue I've been trying to figure out since I heard that there was a dock coming out. Some people say that Sense UI won't go into landscape mode when on the home screen, some of the Desire reviews aren't clear. The dock is definitely landscape (you can see that in the launch packet). But it also says that it won't be available until post phone launch. I'm sort of wondering if there will be an OTA update that will allow Sense to go into landscape before the dock launches. They may have figured it wasn't mandatory to the phone launch. Those are just my musings but it's the only thing I could think that made sense (ha! another pun...)
But a landscape dock with the phone in portrait mode would be absolutely untenable and would make the carrier/manufacturer a laughing stock. So something will have to be done.