You may have read on
battlestar_blog or elsewhere that Katee was recently diagnosed with thyroid cancer. Here are the details from the February issue of SciFi magazine:
"The show ended and then a week later they're like, '...and you have cancer.'" While Sackhoff had felt something was wrong as they finished filming Battlestar's final episodes, she never expected to be diagnosed with thyroid cancer. "It never progressed to a point where it was life threatening. It was thyroid cancer, so it was never a cancer that was going to kill me. But ... it was an awakening for me to really, really stop long enough to let the people that I love know that I love them. ... Everything turned out great. [My] energy level's back up. They got all the cancer. So things are good. [However,] the end of the show was very weird for me, because I wasn't all there."
This undoubtedly explains Katee's absence from Dragon*Con over Labor Day weekend.
If anyone wants to write well-wishes to Katee in the comments to this post, I will see to it that she receives them.