The site for the R4i DSi flash cart posted a video (see it after the break) demonstrating what appears to be the R4i running on a DSi system with the 1.4 firmware. You know, the firmware that was released not even a week ago, and removed flash cart compatibility? Yeah, that one. The video demonstrates a retail game ROM, which is not particularly awesome, but does serve as evidence of flash cart compatibility. The site currently doesn't mention whether this is accomplished through an R4i firmware update or through new hardware. We'll find out more as more flash carts pick up on whatever technique is in use.
If 1.4 has truly been defeated, homebrew users will be able to upload photos to Facebook and play Magnetic Shaving Derby! Magical.