It's all comparisons and expectations.
If Twilight Princess is fun enough on its own, and playable with its controls (this is Nintendo we're talking about, and this is Zelda, they're not going to screw it up) I'm not going to complain about mirroring, or how else the controls were, or whatever.
It's like how Nintendo should've dumped Wind Waker on us without the SpaceWorld 2000 demo.
From what we know, we know that Twilight Princess was ported with controls added, but unless this "patchwork" comes up as actually noticeable shoddiness in the final product, I think we're being pessimistic here. I actually enjoyed Star Fox Adventures (bite me) and Eternal Darkness despite their N64 pre-incarnations. Twilight Princess is different because the previous-gen version will also be available, making comparisons possible, but it comes out something like 11 days later. Guess what? By then I'd have already finished the Wii version and won't care to compare if I ever even did.