In one of Jason's tunnels, there is a wheelchair. One of Jason's victims in "Friday the 13th Part 2" was in a wheelchair.
It took the producers roughly a year to secure all rights so that they could have full use of everything Friday the 13th related (locations, characters, title). This is due to the fact that there were at least three parties who had different secured rights to certain areas of the franchise; with Paramount having rights to the original films they produced and New Line who has bought aspects of the series to create their three films. Eventually all issues were resolved and all parties came together to co-produce the movie.
To fit the "Friday the 13th" theme, there are going to be thirteen kills in the movie. Producer Brad Fuller quoted "To me it seemed like a big number because we were shooting for forty days and that's basically a kill every two and a half days. It was surprising how much work it was to kill thirteen people!"
In an official interview, producers Brad Fuller and Andrew Form decided they wanted to keep the background of Jason and his killing motives to a minimum - a lesson they said they learned when they made the second Chainsaw Massacre. Fuller quoted "This is not an origin movie. We didn't want to spend a tremendous amount of time showing him being ostracized so you see why he's killing. I think that demystifies it in a way that doesn't help."
Photography for Friday the 13th (2009) was wrapped on June - Friday the 13th - 2008.