Since nothing actually altered with the game files whilst the server was down, I would suggest you run a repair on your client. Not saying that will alleviate the issue, just that it -may- and then you won't have to miss out on any additional play time.

I have been able to log in fine and there's plenty of people online so it does not appear to be server side.

To run the repair - open your launcher, locate the news section (where the recent news/clickable links are) and find the "Game Options" text. Select this which will open a drop down list and hit "Repair"

If you had the beta client and updated that to launch client on launch day, chances are that you wont have a Repair option (or other options) in that drop down list. That happened to me and I had to download a fresh game from the site.