I agree. I had to miss the live press conference but had a chance to hear Greta Van Sustern remark later that she'd been hearing about Bush being a "cowboy" and being all gungho after Saddam. She said his demeanor struck her as thoughtful, but determined to defend America. Not at all as if this was something he wanted to do.
So my opinion is if folks like Greta Van were impressed, the tone was the perfect one to take--for the circumstance.
And he betrayed no smirk as he struck the Helen Thomas custom from the event.