I changed my mind since my earlier post insofar as I think the Moto X and the Nexus 5 will be two different devices. Despite the fact that LG has built a Nexus 5 prototype (or rumored to have done so), with all the advanced sensors that the reports say the Moto X will have, there is no way that the Moto X could be a budget "Nexus-like" device. In one report I was reading the phone will know if it is in your pocket, and it will sense your behavior when you remove it from your pocket and go into a different mode. These "Jedi" features can't be cheap and they will require extra software on top of stock android.
I am not exactly sure why this is important or why it would make any difference. Is the reason something along the lines that Motorola, in order to have a successful comeback, needs to focus at first on the Moto X and then go from there? I think it is kind of strange that a direct competitor of Motorola -- LG -- would be making future Nexus devices unless Google and Motoroloa needed more time to integrate.