As for the "guessing" competition. I think that would make Azurea and Happinezz001, as well as an Anonymous user the closest ones.
Azurea was the only one who mentioned elf girl >.<!! Both Happinezz001 and anon have mentioned Myu.
Now, to analyse the cover... well there's Myu, then Letia stuffing herself... and... there's far in the back, Yun, in fluttery white dress! It appears like there's stuff to look forward to. RISE, BELIEVERS.
EDIT: On 20th of may Only Sense Online's short story series is going to start in Dragon Magazine. Hmm.
EDIT2: Added a new coloured illustration to the gallery... and here. Enjoy.