Here's a site with some additional information, including a TODAY show interview with Dr. Bryan Sykes. If his project finds nothing, that will not prove the NON-existence of unknown primates, but I think it will lead to most scientists writing it off (even more than the number who write it off now.)
On the other hand....
Let's take an example: possible sasqutch hair sent in from North America.
The challenge in establishing that a hair sample is from sasquatch is that we don't have a proven sasquatch specimen to compare it to. And certainly it's not surprising that some hair could be mixed: if a bigfoot used an old bear den, for example.
But if Sykes comes back and says something like, "This is a clean, uncontaminated sample with good recoverable DNA, and the DNA is different from all known North American mammals," that will be a very big deal, I expect. At the least, it should create more interest and get more evidence gathered and tested.
I did a little logic exercise here where I tried to imagine what could be the cause if good DNA of an unknown animal was proven.
A ruling of "unknown" could mean only four things:
1. It's sasquatch.
2. The test was messed up. This is unlikely given Sykes' expertise and who he works for.
3. It's a sample from some little-known non-native animal, a South American monkey for example, that someone, for unknown reasons, went and planted way out in the woods. That would be pretty hard to believe, because unless the hoaxer knew exactly where and when a search was happening, any hair sample planted in the woods would be likely to blow away long before anyone found it. Very, very unlikely.
4. There is some OTHER unknown mammal in the area. That's very, very, VERY unlikely.
So I am waiting with everyone else :)