I'm new to the forum and new to DSLR photography, but not so new to Pentax.
My first point-and-shoot was a Pentax back in 1999, and I loved that camera, even though I never really knew how to use it. Then I got a hand-me-down Pentax Optio digital camera a few years ago... and just this week, I got myself an early Christmas present, the K-x.
Since I'm such a beginner, I wanted something that would take great pictures in auto mode, but as I begin to learn how to control all the different aspects of a picture, I can still take good shots. I went into a camera store and held a Canon, Nikon and Pentax, and the K-x had the most appealing/user-friendly menu, and it felt good in my hands. Love that I can use all past Pentax lenses, and the shake reduction was another selling point for me. Also, the price point for all the features (including the ability to shoot video), I just couldn't pass it up.
And I agree with a previous comment, I kinda like having "the underdog" brand, I was thiiiiiis close to getting the Canon Xsi and I'm glad I didn't.