It is looking more and more like it came apart at 35,000 ft. Spreading out the debris field over a very large area.
“Preliminary investigations into missing Malaysian plane are narrowing on possibility of mid-air disintegration - source”
http://www.mirror.co.uk/news/world-news/missing-malaysia-airlines-flight-live-3219331
http://www.reuters.com/article/2014/03/09/us-exclusive-probe-plane-idUSBREA280FF20140309
That does look to be the party line coming out now. While Interpol and intelligence from six countries are there reviewing the tapes of who got on the plane, that is.