To be honest, I'd worry if I was in the anti-virus business. Current free options like MS Security Essentials seem to be pretty good on windows, and viruses aren't exactly at the forefront of mac and linux user's minds. The winds of change seem to be blowing more towards net-enabled appliances, like tablets, and away from PCs. I guess antivirus companies like Kaspersky have to reinvent themselves before the mainstream work out that they don't need to pay for their software anymore, but I'd prefer if they didn't do that by inventing new problems.