I have just made the page for this game but it's not been accepted yet, so I just made this in the DSi Ware forum. 
 
A new BlazBlue game for Nintendo DSi Ware is going to be released in January for 500 DSi Points.  
 
For now it looks like it might just be Rachael, Noel, Ragna, Jin and Taokaka playable as they are the only characters shown on the cover.
The gameplay looks similar to Power Stone taking a less serious approach to the BlazBlue universe. The game also uses "Chibi" versions of the characters. It is a 4 player Royal Rumble style fighting game with ad-hoc multiplayer. 
 
It was shown on Bururaji (Blazblue video podcast) at around 37 minutes they also mention other things like BlazBlue PSP and a drama CD.   



         

Gallery

It looks cute, and I'm all for a little 3D brawler on the DS. I'm not going to complain that it's not a proper fighter for the platform, you cannot expect that from a DSiWare game anyway, I will get my handheld fix of Blaz on PSP instead. 
 
I will get this if it gets a Western release, that may happen after the 360 and PS3 games appear in Europe offically. 

 this could be kinda cool. but...
*gets mad*
DUDE! HOW THE FUCK CAN THEY MAKE THIS, AND NOT PUBLISH BLAZBLUE IN EUROPE!
*calms down, and starts to cry * 
I'll go watch some more blazblue on youtube...

"  this could be kinda cool. but...*gets mad*DUDE! HOW THE FUCK CAN THEY MAKE THIS, AND NOT PUBLISH BLAZBLUE IN EUROPE! *calms down, and starts to cry *  I'll go watch some more blazblue on youtube... "

" @tiwi said:

"  this could be kinda cool. but...*gets mad*DUDE! HOW THE FUCK CAN THEY MAKE THIS, AND NOT PUBLISH BLAZBLUE IN EUROPE! *calms down, and starts to cry *  I'll go watch some more blazblue on youtube... "

PQube are bringing BlazBlue over to Europe in Q12010.  
But yea it does suck we have to wait almost a year since it came out in the US. 
I don't have NTSC 360 but thankfully the PS3 is region free so I still got to play it.   
I also got the HRAP3 BlazBlue stick. :D
    This is not my picture but I have the exact same stuff including the Limited Edition game. "

" @Webby said:

" @tiwi said:

"  this could be kinda cool. but...*gets mad*DUDE! HOW THE FUCK CAN THEY MAKE THIS, AND NOT PUBLISH BLAZBLUE IN EUROPE! *calms down, and starts to cry *  I'll go watch some more blazblue on youtube... "

PQube are bringing BlazBlue over to Europe in Q12010.  
But yea it does suck we have to wait almost a year since it came out in the US. 
I don't have NTSC 360 but thankfully the PS3 is region free so I still got to play it.   
I also got the HRAP3 BlazBlue stick. :D
    This is not my picture but I have the exact same stuff including the Limited Edition game. "

  Nice, I saw that in a London store not long ago.. I passed on it, I think they were doing it for around 120 or 130 pounds "

 Blaz Blue: Battle X Official Site