Josh Silverman, the president of Skype, did a blog post discussing this subject. He was quick to point out that the only people being monitored were the parties using the TOM version of the software. Of course, this also includes anyone communicating with someone using the TOM version. He also claimed that Skype was unaware of this privacy breach until it was surfaced by the Citizen Lab.
Since September, Chinese Skype users have been directed to the TOM-Skype site to download the software. Concerns have been raised that a trojan could be dropped on a user when downloading the Chinese version. A trojan is a form of malicious software, which can be used to steal all the information from a computer.
The full report from the Citizen Lab at the University of Toronto is an interesting read. While there is little doubt from this report that TOM-Skype is being used to track politically sensitive subjects, there are probably a lot of foreigners using TOM-Skype to communicate with loved ones while they work in China. This opens the door for personal information to be stolen and corporate espionage to take place.
Anyone using Skype to communicate with someone in China should be aware that they are being monitored and avoid revealing any personal or sensitive information.