the Nexus 5 (or whatever it’s going to be called) seems like a mildly revamped version of LG’s G2.
No, it really doesn't. The two most-often mentioned features of the G2 are:
a) The gorgeous 5.2" screen; and
b) A 3000 mAh battery; and
c) The rear-panel placement of the only buttons (power/volume), as opposed to the traditional volume rocker on the side that most smartphones have.
This has none of those--it has a 4.95" screen and a 2300 mAh battery. And the buttons are laid out like a standard smartphone. Those things alone are significant alterations that make these phones different in the most visible and usable ways.
The G2 also has a 13 megapixel rear camera; this has an 8 mp camera.
The G2 also has a customized version of Android with knock-on and other features; the Nexus 5, presuming it follows the Nexus pattern, will run a standard Android OS and UI (and get faster OS updates).
Without digging into it for more than 30 seconds, I see a phone with a different screen, different camera, different battery, different physical button layout, and different UI, and with significantly different physical properties (e.g. wireless charging on the Nexus)--these might be distant cousins, but they are most decidedly not "mildly revamped" versions of the same thing.