Steve,
I am currently in this predicament as well: The Canon XA25 or the Blackmagic Design Studio HD Camera. The only caveat i see with the Design Studio HD camera is the fact that you have buy a lens. So what you think is a cheap camera turns out to be quiet expensive once you start to add the extra things you need.
This setup is going to be for my church so what do you think? I am leaning more towards the XA25 because of course it has the SDI output and does not require an extra lens.