Today along with announcements mostly relating to earnings from Nintendo came word of plans for a public (!) 3DS demo event in Japan. Nintendo CEO Satoru Iwata noted that the event will be held January 8, 9, and 10 (three days over the weekend) on the outskirts of Tokyo at the Makuhari Messe convention center. If you'll remember correctly, Nintendo held similar events for the DS and Wii in Japan as well.
Events surrounding the Wii and DS did tours of the larger cities of Japan while this 3DS event seems to be exclusive to Tokyo. You might not have to fly all the way there to get your hands on a 3DS early though, as Satoru noted that there will be "some things" planned that will allow people to play and sample the 3DS in their part of the country (Japan, of course.) So if you live outside Japan, maybe then you aught to get a ticket. If not, take a train, you know, or just hang out and you'll get your try one way or another. This event is the first place any of the public will be able to sample the 3DS