Yes, had this problem a bit ago. I just had to wait a few minutes and then it disappeared. Although it seemed to only be fixing itself for some people at any given time, because when it let me login it didn't let some other people login.
You are correct about that... it seems to only be allowing certain people in at given times. I tried to connect when one of my friends did (like a minute later), but couldn't get in. I guess I missed the window to login. hehe
The good news is, at least, once you are logged in, unless you crash, you will remain logged in and your lobby will list games. Just keep hammering away at that login.

BTW, if anyone was linked here by me from the chat... feel free to say hello! 
Kudos!
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*Remember those patch days in FFXI when you would have server maintenance and not be able to play for 24 hours? Hah, this is nothing!
*This is a BS solution? You are crazy man! This is at least an example of the problem providing some insight... best I have even seen posted about this on the forums all day. Whatever, drive to their server location and fix it!! There is your solution.
*Yes, do not put to much effort into this... try logging in once every 5-10 minutes.