It's hard to tell from the photos, but it looks like it either hit at a very low angle and pretty darn slow and skipped/slid to a halt, or it hit the ground flat as if it was in a spin. Both the vertical tails are bent off the same direction but the wings are largely intact, so if it flipped over on the ground it must have been a pretty weird impact. The cockpit forward of the intakes appears to be missing, but that's where those things seem to break so that doesn't say much.
Offhand and totally from 2 really bad photographs off of CNN, it looks like a vertical impact with the aircraft in a flat spin. It burned so it had fuel onboard. I know of a few malfunctions that could lead to that condition (unrecoverable flat spin) and I also know that the plane can be spun by mis-handling the controls. One F-15E flying from Seymour Johnson entered an unrecoverable spin due to a horizontal stabilizer malfunction and crashed, and they almost roasted the pilot for mishandling the controls until they found the real cause. So there has been one documented case of an F-15E crashing from an unrecoverable flat spin due to a malfunction, and the fairly crummy pictures of the wreckage show what looks like either a low speed flat impact or a nearly vertical flat impact, based on the condition of the burned out wreckage. That's all guesswork and I find it hard to believe that we'll get a chance to inspect the wreckage before it's carted off by locals and third-party intelligence agents.
Oh yea, CNN video showed a nearly intact aim-120 still attached to a missile rail. I bet the Chinese and Russians are currently in a bidding war with whoever possesses that missile, unless we managed to tell the locals that we'd like all of the bits and pieces back and got a chance to recover some of the more intact sensitive parts. I hope that the avionics bays burned or were otherwise thoroughly destroyed...
