Looking forward to the Wii U in just 4 days (Which also happened to be my bday. :3), but still a little unsure about a few things regarding the Wii to Wii U Data transfer, so here goes;

1. Can you still hook up your DS for games like My Pokemon Ranch, WarioWare D.I.Y, Pokemon Battle Revolution. etc. on the Wii U? I'm on 960-ish Pokemon on Ranch and wouldnt want the Pokemon stuck there forever or miss out on the unlockable Mew.
2. Where does my Nintendo Channel data go (Game logs, etc.)? Stunk on the Wii or made the jump to Wii?
3. Suspended Play points in my VC games, transfered or gone?
4. Is everything deleted/transfered off the Wii, or is any data left on there?
5. Is Lost Winds the only game to get left behind, or have others been confirmed?

Think that's all my questions, will post more if I think of any more....

I can answer a few of those. I don't have a Wii U yet, but I know the answer to a couple of those questions.

1. Can you still hook up your DS for games like My Pokemon Ranch, WarioWare D.I.Y, Pokemon Battle Revolution. etc. on the Wii U?
Wii U switches into 'Wii mode' similarly to how the Wii played GameCube games by switching into 'GameCube mode.' I'm very sure you'd still be able to wirelessly connect to a DS.
2. Where does my Nintendo Channel data go (Game logs, etc.)? Stunk on the Wii or made the jump to Wii?
Not sure about this one. I assume it'll transfer over and get placed under the Wii section on the Wii U. No idea if it'd be able to update your gameplay data either. Good question.
4. Is everything deleted/transfered off the Wii, or is any data left on there?
Yeah. Its a full-system transfer. The Wii will become empty like it was when you bought it.

As for the rest, I'm curious about them all too. Hopefully someone out there has the answers. I have one question of my own:

Do WiiWare demos transfer over?

Isn't Nintendo trying (or has done) a fix to allow the transfer of LostWinds?

Excellent questions. I want to know the answers.

And what happens with the 5 player Turbografx games?

Good question.