So older 3DS systems will be obsolete?
Guess all those Fat and Slim PS3 should be steamrolled in the name of Justice huh?
There will always be newer Hardware revisions and Updates for ANY type of Electronics Computers,Smart phones,Game consoles etc........people should Boycott Apple,Samsung,HTC and the list goes on
It's one thing when the new revisions make the device smaller or prettier. It's another thing when the revision locks out the original userbase.
For example, the DS Phat and the DS Lite. You could keep your Phat if you didn't want to upgrade, and you weren't "punished" for doing so. On that note, the DS to DSi is not comparable to this situation. The DSi did in fact have a couple of "exclusive" games, but they were digital only, small budget only, and were basically mini-games or indie tier, not "AAA" titles.
However, from what we understand, the New 3DS will be featuring top end games that are completely exclusive to it. This, in a sense, makes it a brand new console, and not a 3DS in any way but name. Now, this statement will be completely incorrect if it turns out that the "exclusive" New 3DS titles are only ports like Xenoblade. However, if Nintendo starts pumping out AAA titles like Mario, Zelda, or Metroid and make them exclusives, you're going to have a pretty angry fanbase.
Also, on the note of smartphones, your comparison is flawed. New versions of Android devices like Samsung and HTC phones do not "lock out" older devices. I cannot speak for Apple, as I have never used an iPhone before, but my ancient Nexus One I keep in my sock drawer can still run brand new Android apps.