Interesting…  
Spike:  
Fire  
Luna:  
Hm… Sleep? (Kirby Squeak Squad scroll addition)  
Rainbow Dash:  
Most likely a combination of wing, fighting, and jet (probably included due to her incredible speed)  
Pinkie Pie:  
Hoo boy, this oughta be fun… Probably a combination of circus, wheel (because Pinkie), mic, and… Star Rod?  
Rarity:  
Probably a combination of mirror, rock, and magic.  
Celestia:  
Hm… Light? You know, that one ability from Kirby’s Adventure that had no purpose other than to light up dark rooms? That one, but enhanced to deal slight damage.  
Trixie:  
Magic. Nothing but Magic. Amazing Mirror, not Squeak Squad. Just for show, pretty much.  
Derpy:  
Probably just Wing, but slightly weaker and more difficult to do attacks. I’m not sure about this one.  
Twilight Sparkle:  
Hm… Magic, Wing, Ice(?) and… Crash? I dunno. It makes sense, I guess.  
Applejack:  
Fighting, Whip, and Hi-Jump, I guess.  
Fluttershy:  
Most likely Cupid, Leaf, and Animal. Maybe Clean. Maybe.

Words cannot tell how awesome this image is.

duude. yes.