You'll all be thrilled to know that, while we're waiting for the 3DS to get online support, Nintendo has been hard at work ... on DSi Firmware.
There aren't details on what the update does, though it's speculated that it may be preparing the DSi for software transfers ahead of the 3DS eShop's launch. That'd be nice, if only Nintendo would actually tell us.
In the meantime, I'll just keep staring blankly at my 3DS until Nintendo decides I can do something useful with it.
DSi firmware 1.4.2 available [GoNintendo]