The implication is that stone tool usage may not have been limited to humans. It may have co-developed with apes as well. Such a revelation brings us closer to our primate cousins, both in terms of behavior and evolution.
In the NOVA program - The Last Great Ape - which appeared on PBS Television on 2-13-07, Primatologist Frans de Waal discusses our closest biological relatives, chimpanzees and bonobos. He calls them "time machines" because they allow us to look at our species at a much earlier stage of development. Such a study lets us discover aspects of human behavior, thinking, and social interaction that may be more biologically "hard wired" than was previously believed.
The end result may be that by studying chimpanzees and bonobos, we can develop a deeper understanding of who we are as humans.