I think there's a lot more that hasn't been released. When I first learned of today's document dump, and the syringe, I immediately thought about a media report that was in the local media about a week or two after the announcement late last December that the remains found on December 11th were those of Caylee Anthony.
In that media report, it stated that many investigators working on the Anthony case believed Caylee was deceased but felt her death was accidental. It was reported that after Caylee's remains were found, every one of those investigators who had previously thought her death to be accidental had now concluded that Caylee's death was a homicide.
It became apparent that there was something at the scene where Caylee's remains were found that was definitive, something that made it readily apparent that Caylee's death was a homicide. There was a lot of speculation here on what sort of definitive evidence might have been found.
Likely by the end of December 2008/early January 2009, the investigators knew the results of the tests on contents of the Gatorade bottle and syringe. IF there were fingerprints on the Gatorade bottle and/or syringe, and IF there was DNA on the Gatorade bottle, that is now known too.
If any fingerprints other than Casey Anthony's, or DNA other than Casey Anthony's were found, there would have been another arrest in this case. But, there remains only one arrest, and one suspect, and that is Casey Anthony.