So here are the things we know about the LG G3(that we are so sure of):
LG G3 will have a 5.5-inch display with 1440 x 2560 aka QHD resolution
2.5GHz quad-core CPU with Qualcomm Snapdragon 805 SoC
3GB of RAM
13MP main camera with optical image stabilization (OIS) and dual-tone LED flash, 2MP front-facing camera.
Stereo speakers situated under the phone
The LG G3 will have very thin side bezels and the volume keys will be located just under the camera.
Things the LG G3 probabley doesn’t have(that competitors have):
Dual camera like the one on 2014 HTC One
The LG G3 is expected to be announced by May 2014.