The 500 point ($5) DSiWare game was announced in a NicoNico video cast. Four players can pick BlazBlue characters and fight each other with an easy to learn control scheme. Looks like of Smash Brothers-ish with a top down perspective.
Arc System Works will release BlazBlue: Battle x Battle in Japan sometime in January. Aksys is getting into DSiWare games so I suppose they’ll bring this out later.
An unlimited thanks to Len, for the tip!