We are seeing less of the big virus outbreaks such as Sasser and Blaster, and so some people believe the situation is getting better, when in fact it is getting worse. The bad boys are getting more professional and doing more targeted attacks.
As the virus is not new it's 2 years old this could only have happened if those testing computers were not running any anti-virus programs,
There appears to be three different virus writing gangs turning out new worms at an alarming rate -- as if they would be competing who would build the biggest network of infected machines.
The most significant change has been the evolution of virus writing hobbyists into criminally operated gangs bent on financial gain.
It's trivial for anybody to understand how it works, ... To modify the virus is relatively easy, and to change what the e-mail says is trivial.
There might be no attack at all. As everybody knows about the attack, the virus writer may lay low and attack at a later date. The ISPs involved can actively block malicious postings. It's more likely the attacker will lay low or be blocked, rather than succeed.