So, the source of this made me kind of happy cry. The Wednesday Club, a show featuring Amy Dallen, Taliesin Jaffe, And Matt Key on Geek & Sundry focusing on comics/etc, apparently had one episode where their five-minute question was to determine ‘What kind of pony would they be and what would be their cutiemark and name’. Now, I’m used to many ‘popular’ folks outside of fandom treating MLP and fans of it with scorn or ridicule, so I wasn’t expecting a good response. Imagine my surprise to see how excited Amy was and hear that Taliesin loved the seaponies when he was a kid! Even Matt was pretty into it. It made me stupidly happy to see a show I love responded to with such enthusiasm where I didn’t expect and added onto my respect for them. So I knew, teary-eyed, that I had to go and draw their described ponies, so here we have them.  
Left to right, top to bottom:
 
Amy Dallen: Didn’t describe what kind that I heard, but went with the name ‘Scatter’ and wanted some kind of CM dealing with books or metamorphosis. So in the end I went with a butterfly bursting from a book and a pouf of magic.  
Taliesin Jaffe: Went with a unicorn fairly quickly to do with a poisonous flower/plant, in this case with the name Nightshade. For the CM he mentioned a lily with a skull and crossbones. Had to go with the elegant, classy unicorn looks of lion tail and fetlocks, to match Taliesin’s vibes.  
Matt Key: He wanted to be a ‘pegasus with magic’ which seemed like an Alicorn, but I decided to stick with a pegasus. Perhaps he does magic tricks of illusion? Or maybe he’s gotten ahold of something like the alicorn amulet to do magic. Either way, it was decided his name would be Keywee (Keywi?) and his CM should be a bubble pipe to keep it show friendly.