CVG's just published a Nintendo statement apparently confirming that DSi software will be region-locked.
"DSi software (software that is only compatible with DSi) is region-locked, eg: European DSi software can only be played on European DSi consoles," said a rep.
"Nintendo DS software however is region free so you can play any DS software on DSi from any region. You can also browse the Internet on your DSi wherever you are in the world and exchange your photos with friends from around the world."
The company added by way of explanation: "DSi is region-locked because DSi embeds net communication functionality within itself and we are intending to provide net services specifically tailored for each region.
"Also because we are including parental control functionality for Nintendo DSi and each region has its unique age limit made by different independent."
This clarifies a statement made by Cammie Dunaway to Wired after the DSi announcement last week that the console "should" be region-free.
"I believe that just as you can currently buy a DS in Japan and use it here in the US, that you should be able to do that with DSi," said the exec.
More through the first link.