There will be three Google Edition phones and one Motorola X phone in 2013 as per rumors
Now, these are all expected to be sold on the Google Play store. Regular Nexus devices seem to be a separate development though and are not included in this count.
There is one more possible fact that we think is a good indication that the third Google Edition phone will not be made by another company like say LG. That fact is simple - LG is already making the Nexus 4 phone, so it already has a high-end device running stock Android.
In addition to the Google Edition phone information, the same source has also claimed knowledge on the Motorola X situation saying there will be only one Motorola X phone rather than a whole family of X-branded devices. Earlier, Motorola chief executive Dennis Woodside also referred to the Motorola X as a single device.
source: Android Authority