I saw it as the President wanting to say a lot more, but holding back while awaiting more information and world reaction.
I agree with what you've said. It makes sense.
The point about proliferation and terrorist states or organizations was where I got the sense that preemption was on the table.
He didn't say it, but did you hear it that way, too?
I think W realizes that publicly declaring "we are going to nuke the bastards into the Stone Age" doesn't make for a good speech.
" but holding back while awaiting more information and world reaction."
and additional tests by DPRK probably.