Could be, although I've been getting it during the week too.
New error now as well. 11023 unable access server for version check (4:20455,10009,19900,12152). Like it says, when it attempts to connect to the server to check version before even logging in. And the server error thing has become more frequent. I lost count of how many times I've had to re-log since I last posted. Sometimes it errors out right after logging back in, and then there's the wait for the server to recognize that I'm no longer logged in before I can get back, and on top of it it keeps hanging up entirely while trying to load the game after picking a character. The only way out of that is to force-cancel, and it doesn't always succeed in connecting to the game after. This is very, VERY reminiscent of beta now.

I give up for tonight. However, if I do end up unable to complete the event (I'm only missing one ash in Coerthas!) due to these errors, I'll be a very pissed off player indeed.