3DS Lib
The Nintendo 3DS Library.

Can I Play 3DS Games on PC / Mac / Laptop?

As soon as homebrew programmers get hold of 3DS and make a working emulator You will be able to play 3DS Game backups aka 3DS roms on PC and Mac.
Nintendo 3DS EmulatorNintendo DS emulators came out even before the console was released, so You can be sure that Nintendo 3DS emulator is not far away. Nintendo Licensed Game developers who make games for the N3DS already have an emulator that is distributed together with the DevKit, but they are contractually bound from distributing or leaking it into public domain. An early version of DS Emulator (made by Nintendo) called ENSATA - was leaked and can be found online.
Some have raised the issue of regular PC display not being able to display 3D, but lets not forget that all 3DS games support the 3D Depth Slider that can turn the 3D effects off and still let you enjoy the game, so this option will most likely be used on PCs that do not have 3D Ready displays.

Resources:

Nintendo 3DS Emulator
3DS Emulator Download
3DS PC Emulator

DeSmuME - open source NDS emu.
NO$GBA - the best Nintendo DS emulator

NDS ROMs Download Nintendo DS Games
NDS ROMs.com USA
Nintendo DS Roms
NDS Roms Download Be DE

Nintendo 3DS Hardware - R4 3DS

R4 3DS Card - Flash Cards and microSD adapters for N3DS roms R4i DSi R4DS SDHC.
Download R4 DS Roms also known as NDS Games for R4i.

3DS Tech Specs

3DSemu
Download 3DS Games