Speculations in this article are so lame they insult our intelligence. I suggest they release those "previously received letters" side by side with the anthrax letters we have already viewed and let us see the similarities for ourself.
I am a board-certified Infectious Diseases physician with training in medical microbiology.
There is insufficient information in the public domain, including CDC briefings to physicians, to draw any conclusions about either the strain(s) or the degree of "weaponization" of the recent anthrax cases.
It's frustrating, but those are the facts. The rest is speculation.