Twoseaters?

Is there still a need for twoseaters. The new JSF and probably also the F22 will not have a twoseater version. The US navy and marines want to keep twoseaters so they can combine each fighter with different tasks (recon + FAC + electronic warfare = F18G), but USAF is not thinking of new conversion trainer for the JSF. There are a lot of other airforces which have more twoseaters (like the French airforce (rafale B), the IAF (Su 30 MKI) and the IDF/AF (F16D/I)).
Is the US navy planning to buy the F/A 18F as a replacement for the F14 A? Or will the E-version take this job up on him?