For me it started in the morning on the 21st. The day before everything was peachy. That morning I woke up and sent my normal texts that I usually do. The first text sent fine like usual, but anything after would fail to send. One quick-fix I found was to toggle airplane mode before sending a message, which would allow me to send another text or two before failing. The most interesting thing about this issue is that my brother, who is on cm 10.2 started having the issue at the exact same time and we aren't even running the same versions of android.
So I called verizon today and after about a half our I was able to get some information. I told the guy that I had tried rebooting, clearing cache, factory reseting, updating my SMSC number, etc. He said it's probably an issue in their end, which makes sense due to the timing of the issue occurring. He said he would do some behind the scenes stuff and call me back on Monday. I guess we'll see if the issue gets resolved. Keep me posted if you find a solution.