I just visited the site and the following came up as part of the home page: IMPORTANT JAVA UPDATE We have checked the version of Java installed on your computer and discovered that you are running a vulnerable version. You should update as soon as possible. We suggest that you use the Mac OS X automatic software update feature.
Given that I've updated my Java SE 6 twice (2012-001 and 2012-002), unless those updates are defective (which we've all been assured they are not), then the Flashback check site might well be a portal to contaminate one's computer with something nasty.
