When playing Wii games, the Wii U isn't emulating anything. It switches to a hardware compatibility mode and essentially becomes a Wii. And since the Wii doesn't know how to talk to the pad, the pad shuts down. This is exactly how the Wii handled Gamecube compatibility - which is one way to guarantee games will work.
Also, Wiimotes show up just fine for games that support them. There's even an option to pair them in the Wii U's home menu. It's actually rather nice to not have to buy a whole new set of controllers when moving to the next generation for once.
The Wii also never played DVDs, so it's no surprise the Wii U doesn't play Blu Rays, DVDs or any other non-game media.
Oh, and the OS GUI was recently patched to more than halve application switching times and support background downloads.