Update: The AT&T issue has been cleared up and messages are flowing through fast and furious now.
We received word from our partner at Ericsson that there’s an ongoing disturbance affecting SMS traffic over AT&T. For those of us who use AT&T to interact with Twitter over SMS, this is not great news. However, technicians are working on the problem now and Ericsson is throwing in their support as well. We’ll keep you posted.