By this, I mean do they end their life cycle of their consoles and handhelds too abruptly?  When the 3DS came out, I felt that the DS still had a lot of life left in it still.  I mean the DS was set to beat the PS2 record (I am not sure if it surpassed this or not, I know it was close though).  The Wii doesn't have quite as much life as I felt the DS did, but I still think there is still another good year or so with it.  I understand that both the DS and Wii will still continue to sell their fair share.  It just seems like Nintendo is so anxious to be the first into the next generation.   I can't really remember any of the other gens as to which consoles came out first and what not, so maybe they are just trying a new tactic.

Nintendo phenomenally mishandled the last two years of the Wii. They should have, at the very least, brought Pandora's Tower and Project Zero 2 Wii Edition to the US, and kept some of their studios working on Wii games to keep gamers interested. Instead, they left their most successful console for dead. Terrible management.

Nintendo really needs to learn how to do hardware transitions, they always screw them up.

I don't think so, as both consoles are backwards compatible with those devices. Also, in my memory both consoles are really old and it was nice to see the next step taken (especially since sales started to lag by this time anyway).

Pokemon Black & White 2 are coming out on the DS in a matter of 2-3 weeks.

The DS had a long life and a graceful death, so far as I am concerned. Especially since a lot of games have come out since its "replacement." Since the 3DS came out, it has had or will receive Pokemon Black/White 2 and Conquest, Adventure Time, Shin Megami Tensei: Devil Survivor 2, Kirby: Mass Attack, Bejeweled 3, Dragon Quest Monsters: Joker 2, Layton 4, Aliens, Monster Tale, and a bunch of downloadable titles like Zelda. All of this was after over 6 years of life, in a radically changing ecosystem. The DS has had a heroic death.

The past one and a half years for the Wii, on the other hand, have been embarrassing. Part of this is not entirely Nintendo's fault, seeing as the only major 3rd party games released during this time were Just Dance 3 and Rayman Origins. But Nintendo themselves could have done a better job supporting the Wii. Their lateness and refusal to bring over games to the west is just silly, and at very least they could have expanded WiiWare's limits or something to improve the climate. For the greater part of two years though, the Wii was running on Just Dance 2/3 and Skyward Sword, and not much else.

The problem is Nintendo dont have the resources to makes games while trying to launch another. This is where third parties come in. If third parties support the Wii U throughout its lifetime when Nintendo start all their resources into the Wii U's successor it wont die suddenly with no games like the Wii did.

They still could have brought Pandora's Tower and Project Zero 2 to the US; the games were already finished and dubbed in English, they were just a region swap away.

Let Nintendo deliver
they are doing a damn fine job

I think that they definitely killed off the Wii much too soon. It's sales dropped when Nintendo stopped putting out games for it.

The later in a generation you gain a consumer, the less profit he's worth.

Someone who buys a Wii in 2006 is likely to buy a lot more games during the Wii's lifetime than someone who buys it in 2012. Additionally, the games for the Wii will be sold at a far lower price in 2012 than in 2006.

Ensuring the success of their next machine is a lot more important than squeezing out the last 10-20 million of the Wii.