Made in Adobe Illustrator CS6. .AI file here: sta.sh/01r0qog18mkp
. .SVG file here: sta.sh/01sb5xw0dux7
Made this, to celebrate the season 4 premier. By some holy act of Celestia I managed to get just enough internet to stream the episodes, yet not enough to upload this at the time. Sorry!
I also went and made each pony work as a stand-alone, you can find those below.
Individual Pony PNG's (if you want just the image of a single one):
Feel free to use any of the images, just let me know, and credit would be greatly appreciated.
EDIT: Fixed RD's mane & tail outline color, and colors within.