This could be good news. I speculated yesterday that there would be no official acknowledgement of terrorism in this case until they were certain that the sniper threat was either eliminated or seriously diminished. There's no way the White House is ever going to admit that there is something outside its control lurking out there threatening U.S. citizens right in their own back yards.
Just delaying the conjecture as long as they have has probably already worked to dampen the possibility of an explosive public reacton (against mulims in this country), simply because enough time has passed that everyone now "expects" this to be the case -- they've gotten used to the idea.