I can't state exactly what happens, but I have heard that Big N is doing everything that they can to block flash cards.
I don't believe that the 3ds can actually fry a Supercard, but the 3ds has been known to block them and from what I have heard you will then need a old ds to unlock them.
Again this is second hand information only, for more accurate info please visit the supercard official site.
I have an old DS so that won't be a problem, but I've done more reading up on this and I'm seeing conflicting reports that using a Flash card can result on Nintendo bricking the system itself which is concerning to me. It's not like I'm gonna be pirating games, I just want to be able to carry the ones I actually own on a single card to lessen the amount I'll carry on trips.
I got more reading to do I guess, I don't want to spend $200 on a 3DS XL then another $40 on a Supercard DSTwo only to kill my system somehow (assuming these reports are true).
Ok, so I got my 3DS XL now, plus 3 games (all free thanks to saving my old iPhone 4 a little while :)). Now I need to find myself a Supercard DSTwo. RealHotStuff has been recommended to me and I may go with them (using a throw away credit card) but I first would like to see if there are any better places out there, to be more specific one that accepts Paypal.
I have been looking for you and none of the official sites offer PayPal, If you are worried about credit safety you can always snail-mail a check to them.
Yeah. That sucks, I read Nintendo contacted PayPal and got them to refuse to be available to flash card sites. Well I guess I can always use a throw away visa gift card :)
But I will probably hold off just a little longer and wait for some more info on the 3DS scene. I'd hate to buy a Supercard DSTwo then have it become obsolete months later when something like Supercard DSThree (making that up, there's no rumor or news of a SC DS3) comes out and is able to play 3DS backups.
I still have to get a case and screen protectors for the 3DS XL anyway...and Tales of the Abyss :)