If the mash-up of My Little Pony and Doctor Who isn't enough for you, you should know that there's more MLP-geeky happiness: Fluttershy as Dr. Horrible!!
I am a fan of cute and Fluttershy, so you can imagine my high pitched squeal of delight upon discovering this mash-up. I'm not sure how Dr. Adorable started, but I can tell you the source of the image in this post as well as a comic featuring Dr. Adorable (!) can be found on Dr. Adorable's Ask-Along Blog. You'll find lots of illustrations of the timid pony doing her best to be adorable (spoiler: she succeeds) and some funny comics detailing her adventures.
If you fall head over heels, there's some pretty pony-tastic (I can't help that I used that word, watching My Little Pony has affected my brain) wallpaper you can download:
AND! WeLoveFine has a t-shirt design featuring the Dr. here. Maybe I own it.
Finally, someone took the images and words from the Ask-Along Blog and added a voiceover tape. Bejeezus.
This makes other people happy, right?