Wait wat? TP & PH got lukewarm sales? Isn't TP like the second bestselling Zelda of all time & PH the second coming of the Japanese Zelda gamers in terms of sales?
As for your second paragraph of questions, I think it's a mix of the first and second question. People want to see change within the series but at the same time too radical a change will only scare away the veterans rooted in the series' mythos and legacy. There really isn't any more to be said there. I'm very confident however in this series' ablility to deliver though, so I'll be very optimistic for Zelda Wii.
Still below expectations, though. But then maybe Nintendo was overshooting, or comparing it to the Mario games.
And yeah, I buy that. Kinda like what's wrong with Sonic, LoZ needs something to keep it intriguing beyond "Defeat Ganon" and oh yeah, here's a few sidequests.
Now what that would be, who knows. MM thought it was mini-games, WW thought it was fetchquests, MinishCap thought it was interaction, PH thought it was time constraints, the Oracle games had their mechanics...
Who knows.