Should smallpox be destroyed in 1999 as planned?

[Ruth Goldstone]

The WHO has set aside 30 June 1999 for annihilation of the last 
two (known) remaining samples of Smallpox. I believe that they should
 be destroyed ie. because of the risk that they may pose to 
our largely unvaccinated population and because I do not believe that 
live virus is useful in research (ie. The entire 
genome has been mapped and non-contagious cloned DNA fragments are being 
preserved)
  Can anyone offer a valid reason for actually preserving the smallpox
virus?