PBr is going to be a good game to see your pokemon on a bigger scale.
You can get many items in abundance and transfer to your D/P game.
It is also a tester to see how well you can test your abilities as far as battling through the various colosseums.
Each battle field varies on what you can do and which pokemon you are allowed to use. Check serebii.net out for more info for the time being.
Once again no major story line...it just all about battling. We will have to see if they add some stuff for the American Release on June 25th that indicates some kinda stroyline vice what is currently available in Japan.
Trainer: NIKO
Pokemon B/W Friend Code:
3783-4062-8709