Unfortunately there aren't many "unique advantages" WiiU will have compared to MS and Sony's next offerings. The only advantage it might actually has is having Nintendo's games on it. Other than that there's little reason to purchase one. It's gimped hardware in the name of being cheap.
Well I think Nintendo are relying on exclusives, the Tablet and the non-gaming features of the system to differentiate it from the competition.
1) Exclusives are always an advantage no matter what the other consoles contain.
2) The Tablet is an advantage and I don't think it should be underestimated. It's a viable browser, TV remote and game controller. It's not looking like Sony or MS will copy this. Smartglass is about as close as MS will get and that's not practical for gaming scenarios that require both button/stick control AND screen touching at the same time. It's also incapable at the moment of doing full 3d rendering for off TV play.
3) The non gaming features like Nintendo TVii are pretty unique....at the moment. I imagine both Sony and MS will do something like this and they will do it on a much larger scale than Nintendo. Wii U will control the cable box, but it's looking like Durango will actually connect to it. MS are also getting into TV stuff.
Overall I think Wii U's success rests on the Tablet controller selling people and exclusives.
Nintendo's overall design philosophy regarding Wuu has left me rather perplexed. I see little to no reason in gimping the hardware on purpose in order to run at half the power envelope of the current machines. That was stupid of Nintendo to take that on as a main design challenge. If they aimed for the same power envelope we may have ended up with an more powerful console and not the Nintendo Wii60. If they went with the traditional type of power draw from a new console then we'd be getting an actual next gen console. They decided not to do that, but to also throw in a tablet controller that siphons performance from the console as well.
I agree to some extent. There were two things that I thought Nintendo needed to ensure when deciding on the tech in the Wii U.
The first was that it could receive downports from Durango and Orbis. It's hard to predict what the other makers will do but Nintendo could have been pretty certain it's be a seriously good bump over 360. Nintendo seem to have picked the smallest possible jump over current gen that *MAY* make it possible to handle downports but it's looking shaky when you compare known/leaked/speculated specs. RAM, GPU + APU, Speeds etc just seem like a large jump over Wii U.
Second, from a marketting perspective I think having ports from 360/PS3 that ran at least a bit better even if it was just 720p for all games would have helped. As it stands, in the mind of the enthusiast gamer that Nintendo said they want (I'm starting to doubt their actual sincerity here) they needed to ensure those launch ports were really solid and preferably better.
To both these ends I think they should have invested a little more money in the core tech, passing that onto us if they wanted, or at least taking that loss for the first year until they can get manufacturing costs down.
Overall regarding tech, I'm not impressed with what I'm seeing but I do think we'll see games noticeably better than average current gen, especially as engines are retooled for Wii U/Orbis/Durango more modern feature sets. However, the big concern for me is whether they will get those Orbis/Durango downports. If they can't/don't get that, then we will see Wii again I feel. Possibly successful for Nintendo if they can sell the console to the mainstream but potentially barren for us as Nintendo console gamers. What that means is that we then go and buy another console and buy games for that, which means less money for Nintendo.
Nintendo have a very very important year next year and they need to nail it and secure those ports and install base. Next year could start to go totally pear shaped.