Currently, no. However, within the next couple of weeks...possibly after the first larger plot arc, there will be openings for OCs.
However, take this with a grain of salt. If you thought getting a canon through the application prcess was difficult, an OC is going to be extremely difficult. Their personalities and thoughts and history's don't have to be a million pages long, and they don't even have to be complete, as I understand that with some OCs you aren't even sure of their full characteristics.
However, Powers are going to have to be extremely detailed. I am talking strengths, weaknesses, limitations, the whole nine. Not only that, but if they are teenagers, you are going to have to explain their abilities both now, and in the future so that we will be able to know what they evolve into.
For example. Teenage Jubilee didn't yet have her laten ability to charge objects and cause them to explode. That is a very recent mutation that she is just coming into now.
An OC of mine...When I first began playing her, she did not have her latent ability of a flame sheild (she's a pyrokinetic) however it still goes into her bio, because she will eventually be able to do it.
I don't want anything popping up out of the blue powers wise. Meaning if your OC does it in game, there better be a documentation of it out of game.
I wish you guys all the luck in the world with your bios, and hope that with the introduction of canons, comes more people and characters for us to have fun with.
PS - I will require that each player have an established canon before applying for an OC. And if you began neglecting your canon in favor of your OC, your OC will be suspended for a period of time, until we see your posting increase with your canon.