Being surprised by this finding, we had contacted OCZ about their heatpipes. OCZ's Project Manager, Joe Chan, had assured us they were filled with liquid and told us to cut one open. While we had already cut one open, we decided to repeat the process again with another OCZ Reaper HPC DDR2-800 module.
This time around, we decided to use a saw instead and to record a video of the process. As you can see from the video, after opening the OCZ Reaper Heatpipe there was a small amount of liquid that had poured out. It wasn't much, but it was there. All is good on the OCZ front. You can download this video with your Phoronix Forums account from the OCZ heatpipe video page.