Well, not quite...
I've just read an article on MCV
here about the R4 DS Flash Cart and how it could potentially destroy the DS.
Bollocks.
I have a SupercardSD for my DS. It's pretty much the same thing - a flash cart that sticks in the GBA port that uses SD cards as storage. Before you ask, although there ARE DS Games on my flash cart, they are the games I have _BOUGHT_ as it's far easier to carry the one card around than five of them ( yes, I only have five bought games.. I'm a poor student! )
The main reason I have the device though is for homebrew development. Again, highlighting the poor student statement, I don't have the money for an official dev kit ( nor do I assume Nintendo have the habit of letting any random person access to their kits to play with ), so this is the closest I can get.
Homebrew isn't exactly unknown though, each machine has some community built around it developing stuff. There is a problem with it though. Because we're not using official means to get our code onto the machines, we have to resort to often nefarious techniques such as "chipping" them to bypass copy protection schemes and such stuff.
This is where the problem lies.
If you have some means to run homebrew code, you (almost always) have the ability to run pirated games. It basically comes down to the morals of each person as to whether they will stray to "the dark side" and pirate the odd game (or two) along with their homebrew games and things. Though I would advise everyone to not pirate games (at least much) if they'd like to see more homebrew games for their platform of choice, as really you're hurting both developers and the hardware manufacturers.
Should piracy become too rampant, Nintendo will just kill off the flash carts, and that'll mean no more homebrew on the DS. Which will be a shame as there's not many ways for developers to get access to console development without large sums of money to throw around, and possibly an affiliation with a games company that's able to get a devkit in the first place.
So will the rise of popularity with the R4 DS mean homebrew for the masses?
Here's hoping anyway...