A glance through the last couple of pages of posts gives the impression that once again there are some people espousing (or at least suggesting) the utterly ludicrous idea that the rulings in the Guede case could somehow be considered binding precedent for the courts considering the case against Knox and Sollecito. Anyone who thinks this evinces a total misunderstanding not only of the legal system (of Italy or any other civilized nation) but of all common-sense notions of fairness.
This furthermore has nothing to do with the esoteric distinction between the "common law" and "civil law" systems. The principle of stare decisis familiar to those in common-law countries has to do with the interpretation of law by courts; it is never applied to the facts of an individual criminal case! A criminal jury in the United States, for example, is never bound to adhere to the findings of another such jury; each case is supposed to be decided on its own, where lawyers can present a defense; that's an integral part of what "fair trial" means!
Just think about what you're implying if you suggest that the fact that the Cassazione endorsed the conspiracy theory somehow precludes Knox and Sollecito from arguing for a lone wolf theory in their appeal: you're saying that you think the Italian system allows rulings to be handed down against defendants without their having the chance to argue their case! Knox and Sollecito's lawyers weren't at Guede's appeal hearings arguing against the conspiracy theory. In fact, no one there was; there was nobody in those proceedings whose interest it was to do so! Because the prosecutors of Guede presented the conspiracy theory, and his defense certainly wasn't going to argue that he was the lone killer (!), there was no reason for the judges to consider a lone wolf theory at all -- nobody was arguing for it! The presence of culprits other than Guede was effectively stipulated by all parties in that case.
I'm not an expert on Italian law, but frankly you don't need to be for something as elementary as this. The notion that the decision in the Guede case in any way binds the Hellmann court to adhere to any particular interpretation of the facts can be rejected at once, simply on the premise that Italy has something remotely resembling a fair system. For all relevant legal purposes, Guede and Knox/Sollecito are separate cases, period.
Now, if you want to argue that, psychologically, the judges and jurors in the current appeal may be prejudiced because of the Guede ruling, that's a different story, and may or may not be true. I highly doubt they're legally allowed to be (see above!), and in any event it wouldn't speak very highly of them if they were; but my faith in people's fairness did not survive the verdict of the Massei court.