I actually heard about this last Friday before the media coverage began. One of my clients is a close family member of the (former) minister, and there was a scramble to find flights to CMB on Friday .

I think it's a reasonable assumption that you have a near zero chance of being affected by something in the couple of hours you are in transit at the Colombo airport. As SanDiego1K said earlier, the terrorist activity has always been directed at the government, and the usual warnings about avoiding large gatherings, etc. are issued by the State Department for Sri Lanka just as they are for places like Bali.

With the information currently available, I imagine the general opinion here at FT would be to go. As experienced travelers, we learn to weigh the risk of any trip to a "questionable" area using facts and not media hype, but in the end, it's a personal decision. For me, I wouldn't hesitate since I was there earlier this year, and will be back there again in a couple of months. I made my first visit to Sri Lanka in the mid 1980s, and have been going back ever since. Mileage runs are a great reason to visit, but the country and people are also wonderful. But that's me. If it's going to make you slightly apprehensive (and you will be anyway, since it's your first visit) then I don't think that's a reason to call off the trip. But if it's going to worry you to the point of being unable to enjoy the journey, don't go.