Uh huh. Source pl0x. I'm sure it'll be hacked at one point, but how do you know it'll be a flashcart? You seen the PSP recently?
I don't have source on my comment, it is more of some guess works.
First, PSP is using UMD, which is optical storage media. It is not economical to produce blank UMD and let people burn it (one time burn BTW). In fact doing so will only get Sony pissed and went after them. That is why hacker went with memory card approach.
Second, 3DS will feature 3DS, DSi and possibly DS mode depending on the game. Thing is that SD card slot is only accessible in DSi or 3DS mode. No one has fully cracked DSi mode yet, and we don't even know how 3DS game will run. Unless Nintendo excludes DS mode in 3DS (which is possible, since old DS game can run in DSi mode), flashcart will continue to exist until DSi mode or 3DS mode is cracked, allowing SD card slot access.
Third, I'm confused by your statement.
QUOTEYou seem to assume that any cartridge hacked to work on there will load ROMs, and the only reason a homebrew only cart would arise is because the devs crippled it. What if the ROM files themselves are somehow encrypted? There could be many reasons why ROM loading might not work work.