The only way to log in right now is to no-life in front of your PC hammering the start and quit buttons until it lets you in.

I did it for 1 hour straight, got lucky and could play for some hours.

My world (Moogle) was so empty... there were almost no people running around in Ul'dah, just like 4 or 5.

If this crap continues tomorrow and especially this tuesday, they WILL kill the game on its launch day.