No Speculation
A reader in the aviation industry approves of my agnostic approach to the Russian crashes:
The big problem with aircraft accident investigation is that everyone immediately trots out their pet theories. Of course, as you so aptly put it, everyone is spooked on terrorism already, so there's ample room for a knee-jerk reaction right there.
Determining whether or not these were actual terrorist events will take a while, unless some group claims responsibility and has data to back up their claim. The flight data recorders and the cockpit voice recorders all have to be read, the wreckage needs to be examined thoroughly, radar tapes analyzed, maintenance records reviewed, pilot's medical histories reviewed, autopsies performed (you need to look for shrapnel inside victim's bodies), etc., etc.- all of the gumshoe type work. This is a lot different than 9/11, when the whole world saw on video the two airplanes hitting the towers. Even then, if the World Trade Center attacks hadn't occurred on 9/11, but the Pennsylvania and Pentagon ones had, it would have taken some time to figure those out (well, except for cell phones).
Even after all of the investigation is completed, and the probable causes and findings are issued by the appropriate experts, that's still no guarantee of total agreement. For example, there are still a lot of people out there that believe that TWA 800 was downed by a terrorist missile and a government cover-up ensued, even though the evidence is extremely compelling that the NTSB got it right the first time.
Also, even though the odds of 2 aircraft crashing within minutes of each other due to unrelated causes are astronomical, in Russia, anything is possible when it comes to air safety. If this investigation goes like the one on the Kursk (the submarine that sank in the Barents Sea a few years back), it's going to be a spectacular goat rope.
So, to sum- good for you for not even speculating, and sticking to the facts!
Coincidences do occur--all the time. That doesn't mean the crashes were a coincidence, but it's certainly possible.