They will play differently in All Stars. From what SuperBot has said about them, Evil Cole is more of a power house and Good Cole is more acrobatic and technical.
inFamous is my all time favorite series and I'll be maining Evil Cole just like in the games. lol
I have played with both and am pretty sure Good Cole will be one of the very best 1v1 characters. Evil Cole will not be quite as good in 1v1 (but still decent at the very least), but will be much much better than Good Cole in Free For Alls and to a lesser extent probably 2v2s as well. It will be interesting to see though.
Playstation All-Stars Battle Royale Accomplishments:
1st Ever rank 999 (only for full game, not beta)
1st Ever Double Black Belt In 1st 2 seasons (2v2 and Free For All)
1st Ever Black Belt (Acquired in Free For All)
1st Ever 2v2 Player to 300, 400, 500-1300 wins
1st Ever 2v2 Player to Black Belt level 300
1st Ever Free For All Player to Black Belt level 100
2nd Ever 2v2 Black Belt