not likely that the Optimus G will be a Nexus, although they could release an LG Nexus based off the original Optimus G design. It would be a wee bit silly to release the same phone under two names however, especially at the same time...
a Google Nexus device cannot have an SD card slot, as I mentioned in the other Optimus G thread. As this is a patent violation unless Microsoft is getting paid for each handset.
LG Spectrum -- Rooted and running CM10.1 official M2 thanks to TDM (and too many others to list).
B&N Nook Tablet 16GB -- running CM10.1 with 10 finger multitouch