I was able log my vendor char last night directly after maint, after setting up market shop, I attempted to log another char..and was unable to. couldn't log another char all night. After about 9am this morning my vendor was kicked and now I cant' log anything at all.
From what I understand, CO performed maint on the account server last night. I can only assume that there was an issue (as there usually is when they perform account server maint) My guess is that server will be up later today, or at the latest in the morning. This is based on EST in US