For now, only links to the stories—it's still in the "breaking news" stage.
- Salt Lake Tribune: Breaking News: Arrest made in Hacking investigation (posted 12:20:49 MDT)
- KSL-TV: Mark Hacking Arrested for Murder of Wife
- CNN.com: Police arrest husband of missing Utah woman (updated 12:23 MDT)
UPDATE 12:46: The Salt Lake Tribune's site has always been notoriously weak during peak-load times, and today's no exception. The story I link above is not available right now as they attempt to institute some sort of backup plan.
No updates at the Deseret Morning News yet.
UPDATE 12:50: The Trib's story is available again and has more detail than the brief "arrest made, check back for details" statement it showed originally.