“The flight recorder, whose tapes are being deciphered, did not register any pressure on crew members”
Sadly, it's starting to appear that the primary cause of the tragic accident was human error (lack of good judgment) on behalf of the pilot(s) of the aircraft.
Anatoly Muravyov, an air traffic controller on duty at the time, told the newspaper Komsomolskaya Pravda that the aircraft had not been cleared to land and all he and his colleagues could do was watch and wait. He said the "pilot's desire to land at any costs" was, in his opinion, a factor in the crash.
Ever since the story broke I've read a lot of news stories and heard a lot of theories floating around by the press and online comments on blogs around regarding the crash, that the fault was the age of the Russian Tupolev-154, or pressure from the VIP passengers.
As a pilot, I know whenever I hear of a crash of an aircraft, my defenses suddenly come up and I have an urge to "defend" the pilot in charge from wild, misinformed facts. However that urge to defend has to be kept in check as well, least it comes out that the pilot in question was responsible and I defended the actions of an irresponsible, reckless person.
The crash is still under-investigation, my opinion is that as a community of flyers, the best way to represent our art and profession is to hold off on supporting unproven theories or "what if" scenarios until all the facts of the case come out.
My hope is that there were other factors in the case that lead to the accident, however my experience in aviation and from what I've read in a vast amount of other accident reports is that pilot/human error is still a huge factor in a crash. To ignore that and rush to come up with other excuses does all pilots in the long-run a disservice.
UPDATE: The Moscow Times has more information regarding the investigation.