Just wanted to say thanks to everyone again for their input.
I ordered a K200D, charger, 4 gig card, and two sets of Eneloops.
Biggest reasons for choosing the 200D over the XSi.
1) Build quality and ergonomics. The day I placed the order, I went to my local Wal-Mart to try out the XSi one more time. It still felt small and a little uncomfortable in my hand. Like I said, I do shoot with the first generation Rebel for work. I don't know if I just got use to it while working or if it was slightly different or what. In any case, the 200D just felt better in my hands.
2) Batteries. Maybe this is stupid, but I like the AA batteries that one review labeled "arcane" power. My girlfriend pointed out that it would be an unlikely scenario where I wouldn't be able to charge a battery for the XSi, but I still like the feeling that I can pick up some AA's just about anywhere if I need to.
3) Picture quality. I looked for pics from both cameras. Although I found less interesting photographs taken by the 200D, I believe this is due to the proliferation of the XSi. In actual image quality, I found no noticeable difference.***
4) I spent 15-20 minutes talking with two photographers at two different camera shops about both cameras. I was already leaning toward the 200D, but I didn't tell either one, I just asked for their opinions. Both recommended the Pentax over the XSi. One shoots primarily Nikon but has used Canon and Pentax in the past. The other was the owner of a camera repair shop. He complained about Pentax withdrawing their equipment from his shop because he didn't order $100,000 worth of merchandise a year from them, but he still said he'd pick the 200D over the XSi if he didn't have any equipment already. And he shoots primarily with Canon. I know, I know, opinions are just opinions, but it made me feel better about my decision even if that makes me stupid.
I only have one big concern remaining with my purchase:
1) Autofocus. I hope this camera can do what I'd like it to for action sports. If I wanted to take action shots, I shouldn't have gotten the 200D, right? Well, I scoured the Internet and found lots of people who complained about the lackluster autofocus, but I also found people who said it worked adequately and both of the photographers I spoke to said the AF was adequate for what I'd like to do.
I was a little worried because I could find no great action shots taken with the 200D.
If the 200D is capable of regularly producing shots like
these (which were taken with an XSi) I'll be satisfied.