At the 2012 Paris Auto Show, the company did confirm that the LF-CC coupe concept (pictured here) is a preview of a new coupe that Lexus planned to release. And now, they have recently just filed another trademark known as the RC F.
It is clear that the planned coupe will get a higher performance version. Although we can't just speculate or even expect much from just a trademark filing, but the confirmation of a planned coupe from the company gives us some direction in what's coming.
With the trademark filing of the RC F, it is expected that, if the model comes out, it will feature the same naturally aspirated V8 unit from the IS F.