WiiU and backwards compatibility: A Few Questions

A few quick questions regarding the WiiU and backwards compatibility:

1. Can the WiiU play Wii and Gamecube games?
2. How is this done, if it is the case? Via original gamecube or Wii game disks or via digital downloads to the WiiU's HDD?
3. If by downloads does this mean that we only get the games (for backwards compatibility) that Nintendo makes available for WiiU?
4. If (3) does this mean that there's no way I can just purchase a ton of old Wii gamedisks and just slot them in and play them on the WiiU?

My recent experience replaying Wii game on Dolphin Emu (on PC) has led me to think about getting a Wii (again), but if WiiU will play Wii games (and even Gamecube games) it would make more sense to invest in the newer tech.

I'd appreciate any answers you guys might have. I've perused various websites, but nobody wants to explain this stuff clearly. The purchase of a brand new WiiU (black edition with the ZombiU pack-in) hangs in the balance...

It doesn't have GC backwatds compatibility, it does have wii though. Yhe BC works via shoving a Wii games disc in thr Wii U and then playing it.

You can play all Wii game disks in the WiiU. Gamecube is a no go, though.

Also Wii games look slightly better on Wii U.....not dolphin quality but better than through an original wii

I think I'll just add that the Wii U emulates the Wii OS within itself, so you have a Wii app which then launches the Wii menu etc.