Macronix Claims NX Releasing This Year, They are Providing Memory Slots

[Miyamotoo]

Werix357 said:

Nintendo won't be using SD cards for games (unless they plan on giving their games away for free) but a propriety ROM.
(packaging is also a lot smaller), so shipping costs down and manufacturing costs up probably brings them back to even.

The other advantage of having cartridges is hardware will no longer have moving parts or need to make room for a disc drive.
So a home console around the size of an apple TV will be a possibility with the NX.

Also on a side note if Nintendo is using AMD hardware for the NX then there is little chance of the portable being released this year as AMD don't have a low power SoC that is capable of running a portable (at least not at today's standards) yet.

You are right, even 3DS does not use SD, it uses property ROM. 

AMD also has AMR technology, I actually think that ARM SoC (with easy porting from and at x86) provided by AMD will be in handheld and x86 will be in home console.