I'm hoping that somehow in the future they give us an easy way to enter and exit Wii Mode from the regular Wii U Mode and integrate the two shops. That sort of seamless user experience would be very appealing, even if we never get to play Wii VC games on the GamePad.
Honestly though, the most disappointing thing here for me is that my 32 GB SD Card can't be used as Wii U storage space, and thus I need to buy an external USB Hard Drive sooner rather than later. Urgh. I have no idea how to shop for a good Wii U compatible USB external Harddrive other than "Is it 1 TB?" and "Does it support USB 2.0 out of the box?"