I am not a leet hax0r :(
Everything I've read suggests that the evidence against Knox and Sollecito is incredibly flimsy at best, relying on a couple of tiny forensic fragments, while ignoring the complete absence of other forensic traces in the rest of the crime scene. Compare that with other person convicted of the murder, Rudy Guede, who had a history of burglary, whose actual blood-stained palm prints and DNA were found at the scene, and who fled the country afterwards.
The police and prosecution case seems to be that Knox and Sollecito conspired with Guede, who they barely knew, to collectively rape and kill Kercher, staged a break-in, then successfully eliminated virtually all forensic traces of themselves (but not Guede) from the crime scene. It's pretty fantastical, and basically favours an elaborate, conspiratorial narrative over one - that Guede, acting alone, broke in an murdered Kercher - that is most obvious and is supported by the majority of the evidence.
What is true is that the observation of many jurists and journalists that the case against Knox and Sollecito isn't particularly weak by the standards of many murder cases, and that plenty of people are in prison, in both Italy and the USA, on evidence just as weak or weaker. The only difference in this case is that it involves a US citizen in a foreign country, which has lead to greater scrutiny than a purely domestic murder case would receive.
However, that doesn't really say much about the guilt of Knox and Sollecito, so much as the pathetic standard of proof necessary to convict people of serious crimes. We are so far from "innocent until proven guilty" and "proof beyond a reasonable doubt" that it's a joke. Instead, police and prosecutors identify suspects and invent narratives informed by their own suspicions and prejudices, then stick to them doggedly, ignoring any evidence that doesn't support them, knowing that judges and juries will implicitly favour whatever story they tell them.
This shouldn't come as a surprise. We see the same fallacies and prejudiced thinking at work throughout society. The Italian justice probably isn't much worse than that of the USA or the UK, which are just as willing to allow miscarriages of justice happen in order to save the face of the establishment.