I've been lurking these forums for many many years, but this thread made me register up and post.
There was a question asking if you could effectively clone a 3DS via NAND dump and system transfer. The answer is yes, it works just fine with a caveat; if you open the store you *will* lose all your cloned games on the transfer host system and it will reconfigure itself as if it were new.
You can however play multiplayer between the two just fine. It really sucks that Nintendo refuses to adopt a proven iTunes-esque account system.
Pictures for the interested:
EDIT:
To help people avoid bricking their systems, do multiple dumps and compare the md5 hash for each, they should all match.
Finally, open your dump in a hexeditor; if you see a header like this one then you should be golden (no copyright infringing material contained within this).
Code:
=K.."s..=M.j!.......kr.......{\q.....oQ.#H?m. `R.i~T...`H9.Q.....!.......T...z..J.....m\.....Hg.n..e.]c.=.....XEN..?S..C.....u..0...\yN...F1..y.M!...-..nq.=..r....G. ?Mk.N..iQG.......?u....It..z.s..'.N...-J.\..'.G..D.V.!...c.8g.E....#.-.....$M..}1Sm..Vz..(NCSD.