Of course, he is aware of the issue, and provided an update this morning on the ReadBurner blog. (See: ReadBurner Down)
"I knew this would happen sooner or later: ReadBurner is down. My Amazon instance crashed. Argh…"Never one to miss an opportunity to add features, Alexander says he may restart the service from scratch, eliminate double items once and for all, and build improved language filters. The expected time to restart is about three hours. Looking forward to its return.