My $0.02 in putting some of these pieces together....
During the press conference Bush commented:
"To save American lives we must be able to act fast to detect these conversations"
This quote is just one of various hints I've seen over the past few days that seem to indicate that the surveillance that was "authorized" was not a wiretap, but rather scanning of all (?) conversation by an ECHELON type system. The system would attempt to "detect" interesting conversations based on voice-prints and keywords and other data.
The surveillance was not targetted, but rather was a massive fishing expedition. This is something that is beyond the scope of what even a subservient FISA court would allow.