There is little danger of over-hyping this game. If you were around for all the hype surrounding the release of Oblivion, you would realize that it's the same now as it was then, and I don't think it hurt the game too bad, in my opinion. Yeah we didn't get all these far out wishes and speculations we had but overall the game delivered, even if it wasn't walking on water for us. Personally I enjoy speculating, the more outlandish the better. It lets me know that there are other people out there besides me that want these game companies to push the limits of current hardware and game design and it gives the developers a desire and incentive to deliver ever better products. So hype away, hype to your hearts content, the more we push up what we want to see in the game, the more the devs will feel that they have to deliver, if not this generation of games then the next or the one after.
Some of the speculations prior to the release of Oblivion:- Fluid-based dynamic water. 3D water, waves, etc.
- Physics enabled fauna. Grass and etc affected by characters walking through it. Trampled, brushed aside, etc.
- Derformable Terrain (affected by npcs and nature). Rain erosion, landslides, footprints, etc.
- Dynamic Shadows - Everything. The E3 video, nuff said.
- Realistic AI. No psychic guards. Think the thief series but better or etc.
All of the above was speculated at the time, some were taken quite seriously as possibles in the game. The fluid dynamics bit was discussed during an official Q&A with the devs. Whole threads were based around the theme of physics enabled fauna. I remember reading posts discussing how you'll speculatively be able to track animals in the forest based on disturbed grass and stuff.
It's all in fun, even if it isn't going to be in the game. Like someone said, hype doesn't hurt a game, it only hurts yourself if you let it.