When I talk to customers, the different attacks are often something we discuss (obviously). I often mention that Virus and Worm attacks on a broad scale (like Conficker etc.) are a serious problem but at least one we see, one we understand and one we can fight (because we see and understand it).
However, my real concern are targeted attacks on governments and companies as they are incredibly hard to detect. In the last few months, every once in a while we read in the press about an attack on a government and sometimes they went undetected for months until either something happened like a server crashed or law enforcement found out somehow.
This morning I read an article which actually claims that the problem is even bigger than I thought: Report Details Hacks Targeting Google, Others – actually the article just uses the Google attacks to attract the readers as it does not really talk about it but the content is interesting nevertheless