This is just my opinion, but to my mind, everything points towards it being an accident caused by the rebels aiming at what they thought was a different plane. The leaked phone call I posted above and much of the other information we're getting all have to be taken with a pinch of salt, it could...
I think that I read somewhere it's Malaysia's, first then Ukraine, then Boeing, then Rolls Royce. Then after that any country with passengers on board are able to observe the investigation or something like that.
The Russians will hand over the black box after getting/doctoring the data, then...
This is quite interesting... (not in an "open your minds sheeple" kind of way), but seems as legit as any other info we've heard so far...
http://www.kyivpost.com/content/ukraine/separatists-admit-downing-a-civilian-plane-in-tapped-conversation-full-transcript-356545.html