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.
Two disagreements here... 1. I hate people calling the Nexus line "budget" devices. Every Nexus released so far has been a top device for it's niche at the time of it's release. Being offered for a lower price isn't the same thing as being lower quality, like the acer/hp Android devices to date. The reason the GNex, N4, N7 and N10 are so cheap is because Google is subsidizing a huge part of the cost, instead choosing to make their profits from the ecosystem. 2. For now, I completely agree with Motorola being run with guidance from Google, but not being given advantages over other OEM's. The best case scenario for us, is as much competition and variety as possible in terms of hardware options, etc.
I agree the Moto X and N5 will be different devices and my guess is that many OEM's have built prototypes for the contest, but who knows who will be selected. I think LG hit it out of the park with the N4 other than supply issues, and that's a big problem. If they've resolved those issues and gotten a better demand forecast, I'd love them getting another crack at it. So far every Nexus OEM has gotten two in a row (if you count the Dream as a Nexus (it's not, but it's the first Android device, so close enough).