You can pretty much count on all cases not working with the dock.

get a cheap buisiness card hold to stand up the ipad and use the cable. Save money in the process.

@DavidNM: A cable does exist that allows you to use current iPod setups (speakers/docks/clocks/etc) with your iPad.

CableJive Apple dock extender
dockXtender: Dock Extender Cable for iPad, iPhone and iPod

I don't have one, but I know it's going to be useful when I can justify the need for it. I only have one music album on my iPad, so I have no need for the cable. All my music is on my iPhone which I carry around more than my iPad.

Originally Posted by MikesTooLz

You can pretty much count on all cases not working with the dock.

get a cheap buisiness card hold to stand up the ipad and use the cable. Save money in the process.

It looks like the commuter case by otterbox works with the dock. But I don't dock and I don't have that case. So I can't be sure.