I think it's safe to assume that we won't be seeing any sort of 3DS flashcard or hack for at least a year or so, and even when it does become a reality, we'll have to sit through buggy, unreliable methods before we get something like the DS got.
I remember when the DS hacking first started out. I had the original Supercard, which was this giant fucking thing that required you to put an actual cart in it like a Game Genie. It also required the gba supercard to load the rom. What I got was an incredibly inconvenient, super fucking slow thing that barely played any game. I distinctly remember having this in 2005, which was one year after the system was released.
Let's look at the Wii also, for a long time, our only option was to install a mod chip with 20 some connections with soldering pads so small you needed hours and a nearly-professional skill with a soldering iron to get it installed.
Expect this this road to be long and rocky.