Scott!
Smash Lord
Well, we are just fans dreaming of what we think about where the series should go. What we say doesn't really have any bearing on the game, unless Miyamoto secretly reads the boards. And he doesn't. But Spire III said before, though I don't know the source, that they have stated that TP was the last Zelda of its kind, and to expect something different in the future. We're just running with that, looking at what they've done in the past, and guessing what they might do. I didn't seriously think that Nintendo thinks the same as us, though. I'd just like to imagine they do.
However, you say that it's hard to make such different concepts feel like Zelda. While it is a difficult task, they're done a good job so far. Look at Wind Waker. It's completely different from all Zelda games before it in many regards. I don't think having Link go to a new world is any more of a radical departure than having him on an ocean. It was just so different, having all those islands to explore rather than one world. And it really worked well, and ended up being one of the best entries in the series.
Now, I also think it's much more likely they'll throw Link into a random new world than keep him in Hyrule if the next game is a follow-up to TP, which is what I expect. It's worked for them in the past. I mean, just look at how oftent they've done it. They do it often with their first forays into new handhelds. Just look at LA, OA, OS, MC, and PH. Every single original handheld Zelda was in a new world. (Original meaning I don't count the ALttP port or others.) Now, there is a big difference between handheld and console Zelda. But look no further than MM. If it were not for the fact that I played OoT first, MM would be my favorite. It is an amazing game. And it has little to do at all with the normal Hyrule story, at least superficially. Even Wind Waker could be seen as Link in a different world, because even though it was kind of technically Hyrule, it was nothing like the Hyrule we know and love. And both of these games were refreshingly different. I also share a special love for LA, since it was my first Zelda. They do a great job of changing teh formula while keeping it Zelda. I just don't see them staying in Hyrule if the game is going to be very different from all that came before.
Kind of long and rambling, but that's what happens when I start talking Zelda. But back on topic, it's all just speculation on our parts, but it's the best guess I can make. Until we see something from Nintendo (soon please) we can only imagine. I could be completely wrong, at which point, I'll be totally excited for whatever they've surprised me with.
,...wait). A main reason why there all so good (similarly to the mario main series). 
