The technical gap is a little worrisome, but if the Wii U can keep getting slightly lower res ports of all the big games, I don't think they have much to worry about.
Looking at those PS4 specs if the new xbox is anything like that, which you have to think it will be, then the gap is going to be at least as big as it was between 360/PS3 and the Wii. I don't know how long lower res ports are going to last with that gap and the Wii U's sales so far.
As long as developers continue to make versions for the 360/PS3 as well as next gen, the Wii U will remain a dumping ground of ports. Once enough people have made the leap to next gen that developers no longer feel the need to support the 360 and PS3, I think the support for the Wii U will dry up as well.
At least they are able to output 720P with the Wii U, having to use 480i and component cables for 480P is a pretty big reason the Wii looked so shitty on the televisions of today, you really want to be outputting 720P minimum otherwise the scaling becomes really obvious. (especially if your TV is bad at it)
That's a fair point, but there are certainly more technical concerns involved with porting a game down to inferior hardware than simply resolution. If developers don't have a market reason to spend the extra resources to make a last gen version (360,PS3) of their shiny new next gen game, I can't see them spending those same resources to port the game down to Wii U either. Now, I feel like there will be a decent chunk of time where the there are just too many 360s and PS3s out there and not enough next gen early adopters quite yet to justify making a multiplatform game for next gen consoles and not making a last gen version as well, and as long as they are already making a last gen version, it's easy to see that it wouldn't be a stretch to put it on the Wii U as well.
However, once the install base for the new systems gets to a point where last gen development can be retired, there will be little reason to spend the effort to make a Wii U version of most games. We're not just talking about visuals and resolution here. Do you really think the Wii U will be able to run Unreal Engine 4? If not (which I feel is highly likely), a UE4 game would have to be completely retooled to run on that system. Even if the engine they were using was compatible at base level with the Wii U hardware, they would still likely have to use lower detail assets, tone back AI, limit the number of objects that can be rendered at a time, and possibly even limit environment sizes.
What I feel this will amount to is the exact same situation as the Wii, but to an even worse extent for Nintendo. The Wii was the clear cut leader in sales for pretty much the entire generation, but that was still not enough to entice developers to make games for it. Because of the vast difference in technical specs, the choice for developers and publishers was either put a game on the Wii only or put the game on both the 360 and PS3. The Wii had the highest install base of the three, but the combined install base of the 360 and PS3 dwarfed that of the Wii alone, making the decision for developers and publishers easy; a 360/PS3 multiplat could potentially reach more people than a Wii only game.
The outlook for the Wii U is even bleaker, because at this point it doesn't look like the Wii U is going to run away with the sales race like Wii did almost immediately back in 2006. Now, to the point about ports down to the Wii U, it did happen with the Wii, but for the most part they weren't successful enough to justify the development costs to make that port. Just look at things like Skate and Dead Rising on the Wii. Each of these games were severely comprised versions of their HD counterparts, and fans knew it was an inferior experience and mostly avoided them. As the generation went on, you saw fewer developers even attempting to create versions of their games for Wii; there just wasn't much reason to do so despite the system's large install base.
So, if I could bring this back around to the Wii U topic, it looks like Nintendo is going to be in exactly the same situation as last gen regarding third party support. Once developers fully commit to the next gen and stop making 360 and PS3 versions of their games, there just won't be enough incentive to go out of there way creating inferior versions of there games to reach the Wii U audience. And all indications are they would have to go out of their way given everything we know about the specs of the Wii U and what we now know about the specs of PS4 and the likelihood of similar specs for the next Xbox.
Now, I don't think this means that the Wii U is doomed to fail, in fact I will probably be picking one up pretty soon. However, the reason I want a Wii U is for one reason and one reason only; to play Nintendo games. Nintendo has always thrived because of its first party lineup and its a shame they chose to continue to alienate third parties by opting to go with modest hardware yet again, but as long as they make Zelda, Mario, and Metroid games, there will always be people that buy Nintendo consoles. I have a feeling the Wii U will do okay, it's just going to be another situation where if you want to play all the biggest multiplat games, you are going to need to have more than just a Wii U.
PS: Sorry about the novella sized response, thoughts just came pouring out and I couldn't stop them.