I think the reality will be sticking with the status quo regarding AEW. The ASaC kit will be transferred to Merlins and they will certainly be in service for at least a decade and more likely (with a radar update etc) well into the 2020s. I would make an educated guess that a “new” AEW solution will not be on the cards until the middle of the next decade, by which time a whole new breed of airframes and UAVs will be in the frame.

It is the most likely solution to the MASC requirement indeed. And it is not bad, anyway. The Merlin is a proven and very capable platform, and the latest version of the Cerberus radar and AEW suite is good as well.

Of course, i have this dream of mine of an agreement between UK and France… i read a french article, and much as i don’t really know the french language, i think i understood that the french navy is reportedly considering searching an agreement with the british government and have the Prince of Wales fitted with at least a catapult, so that the second CVF can be “shared” and fill a bit of their requirement for a second deck at sea when the CdG is out for refit.
Here is the URL to the article http://www.meretmarine.com/article.cfm?id=113591. Someone may be able to understand it more clearly than i do and share the info in it in this forum.

Anyway, with the french willing to help funding the fitting of at least a catapult to at least one of the two CVF, my dream (probably hopeless, but interesting) is to see a broader agreement being reached, which sees the Royal Navy switching to the F35C and fitting catapults to the CVFs. In that case, the navy would finally be fully and really interoperable with French and US carriers, and the UK and France could pool resources far more efficiently.
In that case, i can see french Hawkeyes flying from the Queen Elisabeth flat top as part of the deal… and the Cerberus-equipped Merlin deployed on Type 45 vessels to improve dramatically their effectiveness against air threats. Or they could be used as mini-AWACS on land, as the Sea Kings in Afghanistan are already doing.

Sharing pilot training with FRance and US, and getting a plane that’s probably going to require less mainteinance than the complex VTOL-geared F35B (and is going to cost less unitarily because built in higher numbers and because lacking the complex lift fan and such) may make this scenario less economically-unaffordable as it may seem at first.
Catapult costs would be shared with the french, if they truly are willing to collaborate: after all, they are not gonna get their second carrier, but they still want to have a deck on the sea.