I'm liking this art style.
I'm not sure if it's intentional, or accidental, but it turned out really nice. What you've gone with is a more slender, attractive look for the ponies compared to the more chunky style of the show, where the characters tend to have more 'meat' on them.
I hope you keep drawing, I can't wait to see your next piece! :3
Edit: That was a few days well spent, my friend