I don't fully disagree with you but I don't really agree with you either. We really haven't heard from actual developers about what the performance of the Wii U is, and we have information that the development kits are under-clocked hardware and probably not based on the customized chip-sets.
Certainly, we won't see "miracles" and the Wii U will not seem to have a massive graphical leap above what the HD consoles currently do; but I suspect that will be the case for Sony and Microsoft's next generation console's too. Primary graphical assets (like character models) have about as much detail as we should ever expect them to, and the impact of increased detail from secondary graphical assets (important environmental features) and tertiary details won't have that much of an impact on the visuals of a game; and most of the graphical effects that will be used in next generation games are already being used on the HD consoles, and the primary difference will be that more of them will be used on an object at a time.
To put it another way, the Zelda Wii U demo doesn't look that much different than what has been done on the HD consoles but what improvements can be made to make it look dramatically better? If this game has a similar jump in visual quality from the tech demo to the released game that we saw with the Gamecube and the N64, what could really be done to make the game look better?
There seems to be this collective disbelief among gamers suddenly that graphics "couldn't possibly get much better," which I think is silly, bordering on ignorant (and I mean no offense as I know people often loathe the word "ignorant"). But we have no idea how much better things can get, and we won't until--really--someone does it. The new Unreal Engine shows graphics that, as it sounds, might not exactly be possible on the Xbox360 or PS3--at least without some kind of compromise.
I find it hard to imagine graphical and engine effects improving much over what we have now, but I've felt this way in the past, and I know that it's just silly to think that things couldn't improve much. Keeping in mind the old rule that computing power doubles every 18 months, and this generation is lasting longer than any other, there are some massively powerful machines on the horizon. Engines are pushing this generation to it's max now--Frost 2 and Unreal and the CryEngine 3.
It's not just general graphics either, it's graphical effects, physics, lighting, reflections, refractions, number of things animating at once, level of animation detail, level of AI detail, number of players playing at once, framerates, size and scope and more. I see all the time where games are limited by modern technology. Blurry, surprisingly low-res textures are in pretty much every game. Gears of War hides it's limitations in fairly linear stages with scripted events. L.A. Noire has some often terrible framerate issues. I see visible seams in polygons. I see textures being drawn in. I see pop-up moving through game worlds. I see clipping all the time.
Essentially, I see the limitations of this generation all over the place now. And I'm sure you and pretty much everyone else sees it, too. This generation has never looked better--but it's also very easy for us to now see it's age. We're used to the current consoles and what they can do, and we're used to their limitations.
I don't know exactly how much better things can get or look, but I know enough to know I shouldn't dismiss how much further things can go. Personally, I don't think a new console generation should ever come about unless true advancement can be shown--a major, obvious leap forward. And it could be that Microsoft and Sony want to make sure they actually can show a big enough leap forward. For Nintendo, it's easy. Pretty much anything they did was going to look better than the Wii.
A new rumor cropped up from GameInformer that Avalanche Studios, the developers of Just Cause, are currently "expecting" a new generation, and new consoles in 2014. It sounds like they don't have Xbox 720 or PS4 dev kits, and are speculating based on their experience in the industry. 2014 is just fine by me, and by that time (if it does turn out this way), we should see some incredible, currently unfathomable improvement in gaming.
After all, in two generations, what was once a "really amazing, detailed and incredible FMV sequence" now pales in comparison to the average gameplay footage of any major disk-based release on Xbox360 or PS3. The leap from PS2 to PS3, or Xbox to Xbox360 was arguably the biggest this industry has ever seen. Why would we dare assume that the leap to the next generation would pale to this? Because graphics seem to have reached an apex? It can always get better! The next generation may feature Bulletstorm-like over-the-top antics without being scripted events. That much insanity, detail and chaos--all in real-time, and dynamic. A game like Prototype with Gears of War-level detail in every corner. No more compromises:
No more "small scripted area in order to have the most intensive graphics." (Gears of War)
No more "stuttering framerates to allow for a detail-rich area." (L.A. Noire)
No more "compromising graphics to fit as much action on-screen at once." (Prototype)
No more low res textures.
No more polygonal seams.
No more draw-in or pop-up.
And if not totally "no more," then certainly, "a helluva lot less."
All I'm sayin' is, we shouldn't dismiss how much further developers can push things just because this generation seems to have reached the top where graphics are concerned. It about a lot more than just graphics, and even those can still be improved.
Nintendo hasn't been interested in pushing the tech of their machines into the stratosphere for two generations now. The GameCube was a powerhouse in it's time, easily more powerful than the PS2 and Dreamcast, but since then, it's been all about conservative power output in their machines. There is no indication that Wii U is pushing any boundaries that haven't already been met (technically) by the PS3 or Xbox360, and that keeps with Nintendo's current style anyway. Microsoft and Sony, on the other hand, I expect them to pull out all stops where hardware is concerned--and I think they'll blow our minds.