A very small percentage of current-generation developers have come close to maxing out the HD consoles. There are games like Uncharted, Halo 4, various open-world games, etc. that do seem to utilize the full potential of the consoles, but they are in the minority. Most games don't come close to the technological prowess of those. Most games only use a moderate amount of power while making games look clean. Hell, a portion of developers aren't rich or skilled enough to push the current gen consoles. That portion will certainly grow next generation. The PS4 and Nextbox will more than likely be more powerful than their predecessar's by a considerable margin. If the average developer only uses X% of the PS360, then I expect the average developer will only use 0.5X% of the PS4 and Nextbox, or perhaps lower. 

Will consumers even care if developers maximize the power of the next generation consoles? Considering the success of the Wii, it's clear that a hefty chunk of gamers are content with even sub-HD visuals. On the HD consoles, gamers don't seem to care if their games maximize the consoles either. The biggest game on the HD consoles is Call of Duty, which most would agree doesn't come close to pushing the consoles to their limits. If gamers are content with a game so weak it that doesn't even push the PS3 and 360, how much power will gamers actually demand next generation?

I'm thinking a very small minority of studios will even attempt to push the PS4 and Nextbox to their limits. I'm not a technology expert, but aside from RAM, most developers don't seem to be too limited with current HD consoles. I expect them to use a much lower percentage of the consoles power next generation. And I don't think gamers will care actually. I personally wouldn't care. I still play games from 2007 occassionally and never find myself complaining about low power or weak graphics. I think we're reaching the point when increased graphical capabilities have smaller and smaller impact on enjoyment. What do you think? How much will you demand next generation?

Will you care?

It's less and less relevant when we get diminishing returns.

I think less devs will actually try to use the consoles full HD power. Though, I do feel like more consumers might start seeing value/difference in "better" graphics this generation since all three of the gaming companies have implemented HD into their consoles now.

No, most developes won't maximize them. Like you said, most don't maximize the current ones. With modern systems the limits are not with hardware, but with development resources. It takes a lot of time and money to program beautiful virtual worlds. As we go forward it takes more and more effort to make improvement in smaller and smaller details. Most players won't even notice these details. Good artistry goes a long way to making something beautiful and that doesn't need a lot of processing power. As long as a game is in hi-def and is imaginatively designed, it can impress me visually.

 Will most developers maximize next-gen consoles?....Most? nope.

And will consumers care?...majority? nope.

That is why I say:

*In terms of the winning candidate

1. Wii-U <--- 1st Party (domination esp. from Retro Studios). Then 3rd party coming on board much more frequent.
2. PS4 <---A lot would disagree but I wont change it. They are like the sleeping giant. 1st party usually comes. 3rd party will be there. Much more affordable console this time around. Free online service etc.. etc.. (Direct competition vs Nintendo 1st party, however PS4 will have very healthy sales).
3. Xbox <---I don't know wtf they doing yet. Kinect? TV 360, 720? etc.... (Unless they do something miraculously then they can go in 2nd but so far all I see is Halo, GOW, Forza) atm

In regards to consumers caring the answer is no. The answer has always been no.

I really don't think consoles need to be crazy powerful. If a manufacturer can produce a console that breaks even or loses a very small amount of money on day one then it will be perfectly capable of meeting most gaming needs. As anyone in PC gaming knows, newer technology scales horribly in terms of value. Making a console a little bit more powerful will cost a lot more money.

 That's the approach I think Sony should take. Microsoft, on the other hand, will likely produce a console that does everything except transform and dance in your living room, but they can easily afford to lose a larger loss per console. However, I think a lot of that price tag will go toward features that aren't necessary related to gaming, so I'm not sure that it will be a lot more "powerful".

Hm, I clearly remember reading throughout this whole year developer after developer complaining about limits of current-gen consoles, and how they can't wait to see new hardware on the market. And considering that lot of them asked for 8GB of RAM in next-gen, I'd say at least some of them have all the intention to push tech quite a bit in next years.

This is why I think memory, and data access should be the focus of next gen consoles. The PS3/360 CPU/GPU are already very capable chips. So much so that as you said, many games don't fully utilize the power available. Most of the time the only major wall the developers run into is how to fit everything into memory. Often times the CPU's on the current gen consoles are wasting massive resources helping move data.

These are the reasons I think Sony and MS are looking to less powerful CPU's for the next gen consoles, and why I think SSD's, eDRAM, and a massive unified memory pool are the most important piece of MS and Sony's next offerings. Any off the shelf CPU and GPU for $100 ea. will more than do the job next gen.

First party will; third party will not, I would imagine. A lot like this gen.