Usually, the product names have to make a change in the last minute due to trademark and filtering. The example is the LG G Optimus. Well, to be pre-caution, LG has gone ahead an filled some name that would possibly for future devices.
A week or two ago, LG applied to trademark the Prime name with specific alphabetical letters: G Prime, L Prime, W Prime, and F Prime. The G Prime would probably continue the G-series, which the younger one would be the G3. The F and L-series indicate a mid-to-low end Smartphones, evidently shows by the F70 and F90. But no confirmation, so for all we know, we could be looking at a very good phone.
The name that stood out is the W Prime. As we know, LG is one of Microsoft’s newest partners. Currently, there is no phone in the W series, and the W could prefer to Windows Phone, similarly to the HTC upcoming Smartphone, the W8, which rumored to be a Windows Phone.
Just so that you don’t get your hope up, trademark some names does not mean new products, and there are possibility that there will be no new phones at all.