Right now, I don't see a very rosy picture for any 5.0 V8.
People, without doubt will be cautious about buying an F car / LC. The price of fuel and tax are concerns. However, the bigger fear would be when it comes to sell the car - how many people will buy it? It may not be so much of an issue with the likes of an IS-F, but the higher priced RC-Fs and especially the LC, I can see difficult to shift. I don't accept the argument that those people that can afford such a car don't care. I personally have considered buying an LC, but I'm really concerned about when it comes to sell it a) What will it be worth b) How easy will it be to sell.
Let's also not forget that a large chunk of the potential performance car buyers out there are mainly interested in performance figures and won't look outside of an M240, M2, A45 etc. I know when I was younger, all I did was look at 0-60 times!