I asked Airfix on Twitter (or Facebook) about an e wing or - saints be praised - a XVI boxing, but their (very prompt, thanks Airfix!) answer was very much in the negative. But maybe they're just keeping it a surprise...if I cross my fingers any harder I'll do myself some damage.
On the subject of AM for the New Airfix 1/24 kits, apart from conversions what is actually needed? Admittedly I've not handled any of them but the reviews etc seem to show enough on the sprues to keep most modellers happy.