Jeff Quinton is liveblogging the crash of one Russian airplane south of Moscow and the disappearance of another between Moscow and the Black Sea. Check in here.
Athena at Terrorism Unveiled has an analysis here. She notes:
Chechen elections are this Sunday, and we know what the implications of that can be. Terrorism is a form of theatrical violence that plays all too well alonside political processes in an attempt to create chaos, the means to an end. (The end being a greater ability to create fear which crushes dissent and is a quicker road to political power. With Islamism intertwining politics and religion, political power creates the atmosphere where a Muslim community, Ummah, is created where there is strict adherence to Islamic law or Sharia.)
It is clear that Russia can be and still is a target of terrorism. I doubt this is one big coincidence and where two planes are lost this close together (with witnesses on the ground saying a large explosion took down one).
We know that terrorists have been doing dry-runs and attempting to assemble bombs while in the air on planes. One was successful and blew up part of the plane and killed the man unfortunate enough to sit in the seat later in the day of the terrorist who assembled the bomb. If the first reports are true, and indeed TWO PLANES have been lost, then terrorism it is.