I was in Turkey in October, including a brief stay in Ankara two days after the bombing, and I never felt unsafe. The people were warm and welcoming -- especially when they discovered that I could speak a little Turkish. I recall that one evening in Istanbul my traveling companion, who was suffering from some neurological issues, was having terrible trouble walking even a few blocks (his troubles forced him to return to the US a couple of days later). A young Arab man came up and helped us get to a bench at a bus stop. (I am not sure how we figured out that he was an Arab because he spoke neither Turkish nor English.) When we were in Konya, we ran into some teenage girls who wanted to interview us for their English class. Everyone we encountered was wonderful.
Security is pretty heavy in major hotels. In Istanbul we stayed at the Bosporus Hilton, and the hotel stopped all vehicles for a thorough inspection, including the undercarriage of the vehicle, before allowing them to approach the front of the hotel. I think they have been doing that for years. Airport-style metal detectors and bag inspections were the norm at all major hotels. In Ankara, two days after the bombing, our hotel was hosting some preliminary meetings for the G20 summit, and the security there was really tight. Not only was there airport-style security, but the hotel was also surrounded with soldiers with automatic rifles. When we first drove up to the hotel, the soldiers are barricades gave us a little pause, but once we got inside the hotel and saw that G20 meetings were going on, we realized why the security was so tight. In museums and such in Ankara, though, it was pretty much business as usual. I never felt unsafe.
I would advise registering with the STEP program with the State Department, just so they know how to get you out of the country in case of an emergency.
Overall, though, I would hop on a plane to go back to Turkey tomorrow if I had the chance. Istanbul and Cappadocia are both magnificent. I can't wait to go back there! I don't think going to Turkey is any more risky than going to any other major city in Europe or America.