I went to check out the DSi Shop last night(9/20/2010), and I was surprised to discover that my DSi wanted me to upgrade the firmware. Unfortunately, I cannot find any substantial information on the newly required update, most of the firmware discussions I've found date back to February or March.
Does anyone know what this new update does? I don't feel like having my FlashCart rendered inoperable by a firmware update.
I've actually found a more recent article, from last week Flashcarts blocked. I'm glad I didn't update.
In general, refuse to update until workarounds are confirmed. I can definitely say in this case that there is zero benefit to updating your Dsi as it doesn't really add to the value of the console with features, it just blocks ****.