I'm wondering if it's a bad segment in a cluster? I've gotten it as well, but it seems to come and go randomly. There doesn't seem to be a specific trigger effect that I've seen, as what I did one time to get the time out works perfectly the next time I do it.
Or, could it be maintenance that isn't announced? A quick 'tweak' to a database or something that takes ESD offline for a few minutes on the test server?
I've had a character stuck in the loading screen for 2hours now. You should get kicked out to Sector Space after 5 minutes or something! I only needed to hit the exchange which I could do other places if ESD is going to crap out.