I am having the same problems. I have been login and playing the game without a problem until today.

I also have the original email with my registration sent on the 27th but nothing since that time.

I am able to login and use the forums, but I cannot login to the game, nor through the final fantasy 14 main website.

Not sure if this is related to the following update:
We were experiencing technical difficulties wherein players were being disconnected from instances on Japan Data Center Worlds. As a result, customers who were disconnected from said content are unable to log in.
Hopefully we can get some feedback on this.