I haven't actually seen many comparisons between how the big 3DS games are doing compared to what the big DS and Wii games did. It's quite interesting in itself, but also hugely important for the future of the 3DS. Nintendo's strategy - at least lately - is largely to release evergreens and have them help sell the system throughout its life, so if that doesn't work, they're in a bit of trouble.

So, I figure there are a couple of ways to make this comparison. One would be to simply compare the 52 weeks of sales of the big ones, and add a comment about the installed base at the time. The problem with this is that it doesn't show much of the future of the games, because the games with big openings will often do well in the first 52 weeks, but not that much from there on and out.

A second method would be to compare how much they sold in a certain week. Such as comparing how every game did week ending 10th November in their second year. This gives a better perspective of their legs, but it suspectible to sudden bumps or irregularities for that specific week. Additionally, it's ridiculously hard to do, due to the data only showing the top 40, so while I'd like to have done this, it's impossible.

A third way is to compare first holiday seasons with other first holiday seasons, and first three non-holiday season with other non-holiday seasons. This should be fun to do after this holiday season has ended.

So as for now, I'll just do the first and possibly something more in this thread later.

There are just three major 3DS games at the moment. Super Mario 3D Land, New Super Mario Bros. 2 and Mario Kart 7. Animal Crossing: Wild Leaf should make this list eventually. 
They'll be compared to the following major DS games, which are: New Super Mario Bros, Mario Kart DS, Nintendogs and Animal Crossing: Wild World. 
Due to the nature of how the Wii developed, with sequels releasing and bundling, the only interesting games to compare the 3DS ones to are New Super Mario Bros. Wii, Mario Kart Wii and Super Smash Bros Brawl.

 I'll start out with first 52 weeks. Obviously, New Super Mario Bros. 2 won't be included here, as it's not been out for 52 weeks.

Note that the attach rate doesn't say that much in itself, but it's an important factor nonetheless. If you just looked at how many copies a game had sold after 52 weeks, games released later in the generation would usually perform better.

Anyway, the two major 3DS games have a very similar situation at the moment. They've more or less been selling identically.

The only DS title that outdid the 3DS ones in absolute sales for the first year is NSMB DS, although it did it at a larger installed base. One could also argue that Nintendogs opening year is more impressive than the 3DS ones too, as it sold nearly as much at a smaller installed base.

Either way, SMLand and MK7 are having similar opening years to NSMB DS and Nintendogs, and better than MKDS and Animal Crossing:WW

 Mario Kart Wii had a ridiculously impressive first year - far more impressive than any of the 3DS games'. But it's interesting to note that after the first 52 weeks, MKWii and MKDS sold nearly identically. Mario Kart Wii sold 17 million more, and Mario Kart DS sold 17 million more.

Overall, we can say that the two big 3DS titles opened worse than Mario Kart Wii (33 million), about as well as New Super Mario Bros DS (29 million) and Nintendogs (25 million), and better than MKDS (22 million) and Animal Crossing, SSBB and SMG (all three 10-12 million).

WOW... this mean that Mario is stronger than ever on ratio %.

Pretty sure I've read many times people say Mario is on decline/reharsh.

Mario 3D Land and Mario Kart 7 are just beasts. Pokemon 3DS and Animal Crossing will end up there, too. And there's a Brain Age 3DS en route as well. Wouldn't be surprised if Super Smash Bros. does very well also.

Nintendogs+cats didn't fair too well on 3DS.
The cats killed the game.

Also, I'd like to add that I think Paper Mario will not be a dud. The sales might look underwhelming now, but I really do think they will rebound in N. America. And in Japan it will do well also.

No where near the others in this thread, but it will be a success. 1.2 million units, something like that.

While this thread may seem to indicate the opposite, their statements are somewhat true. Mario has been in a decline lately, although it's largely due to being in a generation gap. Here's a comparison of the yearly sales. Note that I'm just going by the top 100 yearly data, so all years are actually a fair amount (3-5 million) larger than they appear here. The disrepcancy should be relatively similar every year, though.

In 2012, Mario games in the top 100 have so far sold a bit over 16.5 million.  
In 2011, Mario games in the top 100 sold a bit over 25 million 
In 2010, Mario games in the top 100 sold a bit over 35 million
In 2009, Mario games in the top 100 sold a bit over 37 million
In 2008, Mario games in the top 100 sold a bit over 40 million
In 2007, Mario games in the top 100 sold a bit over 24 milion
In 2006, Mario games in the top 100 sold a bit over 13 million

In the 6th generation (2001-2005) all Mario games in total averaged around 12 million a year.

I'm not sure if Mario will manage to topple 25 million this year, but it should end somewhere in the 23-27 million range. Which is more than a double from the 6th generation, but just two thirds of what it did during its peak.