I'm a huge fan of Animal Crossing, so a 3DS version is great. However, unlike City Folk and Wild World which were basically ports of the first game with not too many differences, it seems like this version will be vastly different.
First off, and probably the biggest thing, you can become the mayor of the town. I suppose it's kind of like being the mayor in Sim City, cause you'll be able to at least place things like benches and lamp posts, though I've also heard that new buildings may be able to be placed as well.
There are also new characters, and old characters have new roles. An example would be Tom Nook is now a real estate agent, and the Skunk that was in the city previously now has his own shoe store in your town. You'll also receive a secretary that helps you out when you're mayor, and a pink llama is taking over the furniture store.
Which brings up something else- there are many more customization options in Jump Out. Since the main character is bigger, it allows for shoe and pant customization, along with the previous options. Your house also has more options. You're now able to mount certain things onto walls, and the exterior of the house is also more customizable besides the color of the roof.
Overall I'm really psyched for this new installment. It doesn't have a release date yet, but it is being released in Japan Fall 2012, so I can only assume that it will be released sometime this Winter or early 2013. Unless the world ends then I'll be really pissed
Also the name sucks asdfsa