I guess the problem with long range weapons on modern airframes is stealthing. It takes an already difficult radar equation and turns it into a two body problem. Carrying a stealth phoenix under a wing would seem to be verrrrry difficult, considering the radar reflection areas that would create, afaict.
I've like to see a new long range missile system, though. My fantasy for this would probably be mounted on an AWACS for defense or launched from a bomber via a rotating dispenser. Imagine something like 4 or 5 AMRAAMs (with datalink) mounted at the nose of a booster stage. It's probably 6 feet or so of heavy booster then a sustainer is built between the missiles, so it's roughly the size of a Tomahawk (but a bit fatter). Your AWACs or ELINT finds the target planes, the launching plane drops it and fires it. The booster pushes the cargo into a high ballistic trajectory, separates, and the sustainer fires. When it is done, the missiles disconnect and either fire or coast and fire later (depending on the situation) up around 120k-150k feet and begin heading towards their targets. With something like this, you could trade maneuverability/accuracy for range (eg, have the missiles fire to boost the ballistic arc then glide in towards targets versus thrust vectored terminal guidance) as needed.
Death from above!
