Up and out early yesterday, so I set the travel mug on the brewer, pushed the button, and walked away to feed the dogs.
Came back. The lid was on the travel mug. Luckily, the sip slider was open, and the coffee had simply brewed through it instead of pouring all over the counter. Phew. There are several ways this could've gone much worse!
One of the nice features of the new Keurig K-Cafe is that it has a "strong" mode. This is usually for making faux espresso shots, but it also works on the full-size cups. I think all it's doing is spraying the heated water through the K-Cup a little more slowly. It's definitely getting more flavor out of each brew, and probably more caffeine.