Gamecube performance is really undershooting the mark. Assuming it sells the same 3 Million/ year as the GC from now on, the Wii U likely has ten years of useful life left and about 8 M already in the market. That's at least a third more lifetime sales. Long console cycles make it easier to penetrate the market deeply.

Really, the Wii U's major adoption arguments will come in two waves. The first wave, the "Nintendo games" is starting later this summer and fall. This will probably spur enough sales to garner third party support again and you'll see some really unique exclusives in the 2014/15 range.

The second major argument comes 2015-7, when many early-adoption gamers will already have a Gen 8 system and will again have disposable income burning their wallets. Between a mostly exclusive library and allowing entertainment centers to multitask, the Wii U is the logical second system choice. Especially if it manages to remain cheaper than the competition this far into the generation, which is not a granted when you need a touchscreen tablet controller.

I don't see the Wii U matching the Wii, or even coming close, but it will probably land somewhere around where the 360 and PS3 are in sales right now: mid 70's million units sold.

I doubt the PS4 or Xbox One will be as monopolistic as the PS2, many of Nintendo's franchises are more popular now thanks to the Wii, and there are more console gamers now than there were during the GC era. Taking all of that into consideration I absolutely think the Wii U will see better sales than the cube. I think the real question is how much better will they be?

Don't you mean the opposite of that?

No, I honestly can't. I mean it has been doing worse so far and it was launched a year ahead of the competition rather than a year behind.

You should seriously look at what the final sales of the GC are and look back at the Wii U's current sales figure.  Then think about the games that the Wii U is getting that's for sure going to boost sales.  Are you certain?

edit: my bad, double post.

Of course I'm not certain, I hope I'm wrong. But I don't know what I should be looking at? GC ended at 21.74m, Wii U is at 3.18m, but what should this tell me? What I am currently going by is when you compare Wii U and Gamecube sales month by month from launch, Wii U is under (a fair amount) every time.

Games are a question mark really. What will the Wii U get that the Gamecube didn't? Maybe something like Wii Fit U will take off, but who knows? Everything else was on the Gamecube.

Well, a good bit of the series Nintendo has have grown since then as well.  

I'm confident to say that games like the 3D Mario and Mario Kart will boost sales substantially, and boost the momentum of the Wii U.  That alone should be enough to push it past the GC and there are still games we don't even know about yet that are coming that all have the potential.  I think chances are in the Wii U's favor.

I have no doubt it'll outsell the Gamecube. How much more than that it achieves is all up to better marketing, aggressive pricing and, most importantly, whether or not Ninty finally introduces a game that truly proves the Gamepad as a game changer.

this =)