Exactly same here. I bought a premium service few weeks ago, and all was excellent until yesterday. Today is the second day that they are down, and all information they provide is that:
https://lavabit.zendesk.com/entries/25122581-Maintenance-2013-08-07-4-30am-CDT-UTC-05-00
It´s already annoying that the servers are down so long, but their information policy is the real disaster...