The total number of detections in the years prior to 2007: 250,000.
Total number at the end of 2007: 500,000.
In other words, it took just one year to double a number reached over a 20 year period.
F-Secure is quick to point out that most of the new malware detected were variants on past code: "Genuine innovation appears to be on the decline and is currently being replaced with volume and mass-produced kit malware."
However, there is not really much consolation or comfort in this. The research indicates that "while new techniques weren't developed—the existing techniques were refined and adapted for much greater effectiveness. There are some very dangerous faces in the big crowd."