Jump Superstars is a lot like Super Smash Bros. in retrospect. The gameplay is very similar but it borrows from "Shonen-Jump" which has some awesome characters to enjoy. Naruto and Bleach's Ichigo for example... The level design is sub-par however... The only way to get the game is to import sadly and it has no plans of a United States release.
As far as the DS handling SSB, I can see it happening. After some of the skirmishes I have played in Metroid Prime: Hunters, I am almost positive the game could be toned down to be playable.
With the extensive amounts of fans, it would be insane not to even try... With NDS-Lite sales through the roof, Nintendo should know their sales would be amazing...