It looks like some HTC Android phones which install malicious applications could have their Wifi passwords stolen according to an article by Network World last week.
HTC has released some patches to their software to help fix this issue.
Although this might only affect a small subset of Android users, it brings to light some of the precautions we should all be taking when using our mobile devices. Make sure to look at the permissions that applications need and make a decision as to whether or not the risk is worth the application. Only install applications from trusted sources, and realize that the Google Market may not always remove malicious applications.