First off, she dismissed the popular notion that manufacturer's skin overlays on top of Android's stock interface are the reason for the delays. The main culprit is apparently hardware - the more chipsets and baseband radios for different carriers or countries a manufacturer uses, the more complicated it gets to adjust the code for each and every one.
She said it's very simple to update Windows Phones, for example, as there is only one standardized chassis, or even Sony's smartphones, since they only use Qualcomm chipsets. For Moto, however, it is more complicated, because the company uses a number of chipsets and radios from different manufacturers, and it takes time to tailor and troubleshoot them all.
Nothing we haven't heard already from Sony, for example, which came to similar conclusions in their own explanations what's taking so long for Android updates to reach our handsets, but it's nice to have a confirmation. Despite all these hassles, Motorola's exec said that the company has been pretty quick with updates so far, and has often been the first out of the door with the newest Android version for some of its gear.