Don S. Davis, General "Homer" Hammond, Scully's dad, and a whole crap ton of other roles has passed away, apparently from heart failure.
As I was saying to Aj, this totally sucks, and hurts all the more because I'm nose deep into watching my SG-1 season four DVDs, and there's just some great stuff in here for him, although he did just die, off-screen, in the episode I watched, so that was a little creepy.
If you watch anything, you've likely seen him somewhere before, the guy's been in everything. What a career he's had.
So long, Don, the SGC just wasn't the same without you, and now it never will be the same again.