The judge just tossed a lot of the evidence against Bonds for being inadmissible hearsay. For prosecutors, the problem is that Greg Anderson still isn't talking. He's the guy who could tell the story, and he's not going to say anything. (Why? Beats me.)
Is that all bad? Perjury is bad, of course, but does Bonds really deserve to go to jail? I dunno. If he does, it won't be for long. As I've said before, don't lie to the Feds.
Quick Hearsay Review: Inadmissible hearsay is evidence that exists (in this case the test results) but can't be used in court. I still remember my Evidence professor saying that hearsay is 'an out of court statement offered to prove the truth of the matter asserted.' Here, all those test results are statements that were made outside the court, and the prosecutors are trying to use them as evidence. Hearsay actually has lots of exceptions, but apparently the judge didn't think that this evidence fell within any of them. The reason the rule exists is that we would prefer that evidence be offered by a live witness. In this case that witness would be Bonds (who can't be forced to say anything due to the Fifth Amendment) or Anderson (who won't testify).