I think what MMMommy said is right - if you can go and not be too worried, go and have fun!
We are going for the weekend. I am not sure if it's the right thing, I'm definitely uneasy. I think the travel advisory is for international travel, although of course still be aware while in busy areas of the US.
I have to tell myself it will be fine. No one actually announces where/when they're going to attack.
Good luck with your decision. Enjoy whatever you do!
ETA: I posted a similar question about NYC at Thanksgiving, the majority said to go.
"Every mother needs a wife." - Amy Poehler, Yes Please