It's not known for sure if it's a permanent change. Ron Perlman took over as narrator when the first season began regular weekly airings in February 2009 starting with 'Tweets of the Dead', Joe Irwin assumed narrating duties (Perlman's voice is still used in the disclaimer and title sequence). The series aired two pilot episodes on Spike in May 2008, with Thom Beers (owner of Original Productions, the company that produces the series) narrating. The final story of each episode, up until season one, shows actual footage of dangerous situations that almost ended in death, along with interviews with those involved, who survived. Each episode also includes commentary from various experts on the science behind the deaths. Names were changed to avoid lawsuits, but the stories are based on actual events- supposedly.
Spike TV's 30-minute anthology of people dying in spectacular, gruesome and often stupid ways.