I think its unfortunate Nintendo went with 3D as the "trick" on this system. Sure it might lead to some interesting effects in some games but I can already see myself and most other people setting the 3D slider to "Off". At least they were smart enough to have the option to completely disable the 3D.
As an updated DS, larger screen, analog stick, etc I think it will do fine just as it is even if the 3D fad passes through. Theres very little for my to go buy one anytime soon, now with the price as high as it is or the current lineup. It'll be a nice system to grab a few years down the road.