I'm glad it's coming out for the 3DS, it's about time. I don't think it'll be the end of Pokemon - people will just upgrade to the 3DS, like they did with the NDS when Diamond and Pearl came out.
As they should too, it's an amazing system and so many people bash it unnecessarily :\
It can play original NDS games as well as the 3DS games [obv] and has a great eShop selection, fun apps, and quirks like StreetPass. It really is a huge step up from the NDS.