We may never know more than that. Not for sure.
It seems clear the plane was brought down by a missile, and the simple physics of the circumstances rules out a shoulder-mounted model. But will we ever know who fired it? Probably not.
A lot of answers might have been found in the debris field. However, the debris field is under the control of what can only be called irregular forces. Whether they're freedom fighters or terrorists, they're not disaster specialists, and their first priority is not preserving the area for professional crash investigators. (I'm also not sure how they can be certain all the debris is within the perimeter they've apparently established.)
At this point, no real investigation is possible: the integrity of the site has been fatally compromised in the eyes of the world, whether or not the irregulars actually have tampered with it. Even if we found the voice and data recorders, it's doubtful they could shed much light: it hardly seems likely either mechanical fault or pilot error accounts for the crash.
What about data sources not at the mercy of the irregulars: signals intelligence, satellite surveillance, eyewitness observations? Unfortunately, they all come from sources that may wish to mislead. Anyway, the idea that the U.S., for instance, is going to make public its spy satellite data is laughable.
Barring a miracle, "the" story of flight MH-17 will probably depend on whom you believe. It's not likely we'll find out more than we already know — or suspect.