The picture above shows the hollow shaft on the drive side. This shaft is indeed hollow all the way to the other side. FSA's installation procedure (summarized) is to install both bearing cups, then slide the crank shaft through both cups. The right crank is integrated with the shaft, so the only thing left to do is to install the left (non drive side) crank. After sliding the crank onto the shaft, you screw a small cap that is similar to a dust cap which pushes the left side crank onto the shaft and against the outboard bearing. There are 2 allen bolts at the end of the crank (opposite of the pedal end) that are visible in the picture. These are then torqed and installation is complete. The hollow shaft replaces the old solid shaft in square taper/Octalink/ISIS bottom brackets. The black thing you see in between the 2 silver BB cups is just a dust cover; the shaft is inside. When I get home I'll email you some pictures.

For those wondering what the "MegaExo" hype is about, the picture below illustrates how much bigger the bearings are versus a standard ISIS crank. The top BB is standard ISIS, the one below is a FSA "Howitzer" bottom bracket for those with nice ISIS cranks who would like to get the benefits of MegaExo technology. Which would you rather ride with?