Numerous US realms were pulled down starting this morning because of unspecified problems which may be related to the cross-realms battleground system. Tseric only provided us with the information that the realms were remaining offline because they were undergoing battlegrounds testing, but this may have something to do with the problem of missing characters
as well (as the final realms offline for maintenance seem to match the realms with missing characters). However, all realms should be back online and running as of 3:10 PM PDT. If you're still having problems, however, you may wish to page a GM or post about it in the customer service forums.