i'm going to shout 'F/A-18E' here - given how long its going to be before we've got say 25 Daves and enough carrier qual'd pilots to make actually owning a carrier worthwhile, we'd just be better off going for a 'bridge' SuperHornet programe. if we bought now, in 2012, we could spend the 7 years until PoW enters service learning to fly it, fight it, maintain it and use it on a carrier, then as soon as PoW comes on scene we'd be ready to rock, rather than waiting yet another 4 years or so until RN/RAF pilots are sufficiently trained on the beast to be able to use the carrier effectively.
from what is written here it looks like it will be 2025 before the carrier, aircraft and crews are ready to operate ogether. by buying SuperHornet we'd have that operating capability in 2019/20 - and we'd have a proven multi-role aircraft able to take over Tornado's role well before that.