There is also a video of the magazine, uploaded by YouTube user zammap, for anyone who remains skeptical.
Equestria Girls is a companion series to Friendship is Magic, set to premiere in the spring. Our pony heroes set off on an adventure to a new world--our world--where they will take on human forms. This does not interfere with the main series. Friendship is Magic will continue as normal and, I am assuming, have little to do with Equestria Girls outside of using the same characters. The article also states that My Little Pony is a "top-priority" brand for Hasbro so "expect [Friendship is Magic] to continue to explore new themes and storylines until Twilight Sparkle retires to her paddock".
It has also been rumored that Equestria Girls will spawn human dolls of the ponies based on details stated in Hasbro's Equestria Girls IP filing. As we have not seen evidence of it yet, it remains a rumor, but it seems highly likely at this point.
Unconfirmed rumors claim that the upcoming My Little Pony movie will launch the spin-off series, but as the article does not mention it, I cannot confirm it to be true.
Under the cut is "leaked" concept art from Equestria Girls. As there is no confirmed source, these may or may not be what the human ponies look like. Images feature the mane six and Trixie Lulamoon.
(via Equestria Daily)