I don’t know. I’d go, but just be a little more aware. I was in Madrid last week and I went to the opera...and for the first time ever, I saw machinegun toting police outside of each door, because it was a crowd venue and they had received and acted on a warning about attacks. The Spanish had arrested a set of Moroccans intent on stabbing people in the streets of Madrid about a week before I got there, and while I was there, I saw arrests everywhere, ever in the quiet neighborhood where I usually stay.
Since 3/11 (Madrid train bombings) the Spanish have gotten much better on this stuff, and I think France may have had its wake up moment. I think the only problem will be cumbersome security procedures, but otherwise, you’ll probably be as safe in Europe as anywhere.
Maybe Syria will be the newest tourist destination? Most of their young men are roaming the world looking for infidels to murder or rape or assault. Maybe it is only elderly, war-shocked, women and children who remain in Syria.