The Nintendo DSi may come with an SD card slot, prompting fears of even easier piracy, but the redesign will close the boot exploit that allows flash devices like the R4 to load arbitrary code.
According to this story on DigitalBattle, the new DS model will crash if you try to boot with an auto-booting flash card in the slot. Menu-bootable cards will load, but the DSi will crash as soon as a menu item is selected.
On the one hand this may make a dent in game piracy, but it looks like it will scupper legitimate Homebrew developers too. Hopefully Nintendo will be able to come to some compromise - possibly involving that intriguing SD slot...
Flash Cards No Longer Work on DSi [DigitalBattle]