Regarding a pure A-A module, I think an F-15C is already in the works, but I'd rather have something that can sling a few HARM's first then switch to a CAP role. Would be less frustrating for the hog drivers and allow for realistic mission scenarios with SEAD and escorts.
I'd personally HATE to see a low fidelity (and it would be) F-22 or JSF, as I fear it would attract the instant gratification generation and provide them with an idiot proof 'God mode' aircraft with which to 'pwn' us all.
I think FC3 covers the A-A role well enough for now anyway, filling a gap before the 'real' fighters arrive and hopefully being slightly inferior to them when they do (for a well trained pilot anyway).